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Diffstat (limited to 'libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jquant2.c')
-rw-r--r-- | libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jquant2.c | 2622 |
1 files changed, 1311 insertions, 1311 deletions
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jquant2.c b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jquant2.c index f7e351f..38fc2af 100644 --- a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jquant2.c +++ b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jquant2.c | |||
@@ -1,1311 +1,1311 @@ | |||
1 | /* | 1 | /* |
2 | * jquant2.c | 2 | * jquant2.c |
3 | * | 3 | * |
4 | * Copyright (C) 1991-1996, Thomas G. Lane. | 4 | * Copyright (C) 1991-1996, Thomas G. Lane. |
5 | * Modified 2011 by Guido Vollbeding. | 5 | * Modified 2011 by Guido Vollbeding. |
6 | * This file is part of the Independent JPEG Group's software. | 6 | * This file is part of the Independent JPEG Group's software. |
7 | * For conditions of distribution and use, see the accompanying README file. | 7 | * For conditions of distribution and use, see the accompanying README file. |
8 | * | 8 | * |
9 | * This file contains 2-pass color quantization (color mapping) routines. | 9 | * This file contains 2-pass color quantization (color mapping) routines. |
10 | * These routines provide selection of a custom color map for an image, | 10 | * These routines provide selection of a custom color map for an image, |
11 | * followed by mapping of the image to that color map, with optional | 11 | * followed by mapping of the image to that color map, with optional |
12 | * Floyd-Steinberg dithering. | 12 | * Floyd-Steinberg dithering. |
13 | * It is also possible to use just the second pass to map to an arbitrary | 13 | * It is also possible to use just the second pass to map to an arbitrary |
14 | * externally-given color map. | 14 | * externally-given color map. |
15 | * | 15 | * |
16 | * Note: ordered dithering is not supported, since there isn't any fast | 16 | * Note: ordered dithering is not supported, since there isn't any fast |
17 | * way to compute intercolor distances; it's unclear that ordered dither's | 17 | * way to compute intercolor distances; it's unclear that ordered dither's |
18 | * fundamental assumptions even hold with an irregularly spaced color map. | 18 | * fundamental assumptions even hold with an irregularly spaced color map. |
19 | */ | 19 | */ |
20 | 20 | ||
21 | #define JPEG_INTERNALS | 21 | #define JPEG_INTERNALS |
22 | #include "jinclude.h" | 22 | #include "jinclude.h" |
23 | #include "jpeglib.h" | 23 | #include "jpeglib.h" |
24 | 24 | ||
25 | #ifdef QUANT_2PASS_SUPPORTED | 25 | #ifdef QUANT_2PASS_SUPPORTED |
26 | 26 | ||
27 | 27 | ||
28 | /* | 28 | /* |
29 | * This module implements the well-known Heckbert paradigm for color | 29 | * This module implements the well-known Heckbert paradigm for color |
30 | * quantization. Most of the ideas used here can be traced back to | 30 | * quantization. Most of the ideas used here can be traced back to |
31 | * Heckbert's seminal paper | 31 | * Heckbert's seminal paper |
32 | * Heckbert, Paul. "Color Image Quantization for Frame Buffer Display", | 32 | * Heckbert, Paul. "Color Image Quantization for Frame Buffer Display", |
33 | * Proc. SIGGRAPH '82, Computer Graphics v.16 #3 (July 1982), pp 297-304. | 33 | * Proc. SIGGRAPH '82, Computer Graphics v.16 #3 (July 1982), pp 297-304. |
34 | * | 34 | * |
35 | * In the first pass over the image, we accumulate a histogram showing the | 35 | * In the first pass over the image, we accumulate a histogram showing the |
36 | * usage count of each possible color. To keep the histogram to a reasonable | 36 | * usage count of each possible color. To keep the histogram to a reasonable |
37 | * size, we reduce the precision of the input; typical practice is to retain | 37 | * size, we reduce the precision of the input; typical practice is to retain |
38 | * 5 or 6 bits per color, so that 8 or 4 different input values are counted | 38 | * 5 or 6 bits per color, so that 8 or 4 different input values are counted |
39 | * in the same histogram cell. | 39 | * in the same histogram cell. |
40 | * | 40 | * |
41 | * Next, the color-selection step begins with a box representing the whole | 41 | * Next, the color-selection step begins with a box representing the whole |
42 | * color space, and repeatedly splits the "largest" remaining box until we | 42 | * color space, and repeatedly splits the "largest" remaining box until we |
43 | * have as many boxes as desired colors. Then the mean color in each | 43 | * have as many boxes as desired colors. Then the mean color in each |
44 | * remaining box becomes one of the possible output colors. | 44 | * remaining box becomes one of the possible output colors. |
45 | * | 45 | * |
46 | * The second pass over the image maps each input pixel to the closest output | 46 | * The second pass over the image maps each input pixel to the closest output |
47 | * color (optionally after applying a Floyd-Steinberg dithering correction). | 47 | * color (optionally after applying a Floyd-Steinberg dithering correction). |
48 | * This mapping is logically trivial, but making it go fast enough requires | 48 | * This mapping is logically trivial, but making it go fast enough requires |
49 | * considerable care. | 49 | * considerable care. |
50 | * | 50 | * |
51 | * Heckbert-style quantizers vary a good deal in their policies for choosing | 51 | * Heckbert-style quantizers vary a good deal in their policies for choosing |
52 | * the "largest" box and deciding where to cut it. The particular policies | 52 | * the "largest" box and deciding where to cut it. The particular policies |
53 | * used here have proved out well in experimental comparisons, but better ones | 53 | * used here have proved out well in experimental comparisons, but better ones |
54 | * may yet be found. | 54 | * may yet be found. |
55 | * | 55 | * |
56 | * In earlier versions of the IJG code, this module quantized in YCbCr color | 56 | * In earlier versions of the IJG code, this module quantized in YCbCr color |
57 | * space, processing the raw upsampled data without a color conversion step. | 57 | * space, processing the raw upsampled data without a color conversion step. |
58 | * This allowed the color conversion math to be done only once per colormap | 58 | * This allowed the color conversion math to be done only once per colormap |
59 | * entry, not once per pixel. However, that optimization precluded other | 59 | * entry, not once per pixel. However, that optimization precluded other |
60 | * useful optimizations (such as merging color conversion with upsampling) | 60 | * useful optimizations (such as merging color conversion with upsampling) |
61 | * and it also interfered with desired capabilities such as quantizing to an | 61 | * and it also interfered with desired capabilities such as quantizing to an |
62 | * externally-supplied colormap. We have therefore abandoned that approach. | 62 | * externally-supplied colormap. We have therefore abandoned that approach. |
63 | * The present code works in the post-conversion color space, typically RGB. | 63 | * The present code works in the post-conversion color space, typically RGB. |
64 | * | 64 | * |
65 | * To improve the visual quality of the results, we actually work in scaled | 65 | * To improve the visual quality of the results, we actually work in scaled |
66 | * RGB space, giving G distances more weight than R, and R in turn more than | 66 | * RGB space, giving G distances more weight than R, and R in turn more than |
67 | * B. To do everything in integer math, we must use integer scale factors. | 67 | * B. To do everything in integer math, we must use integer scale factors. |
68 | * The 2/3/1 scale factors used here correspond loosely to the relative | 68 | * The 2/3/1 scale factors used here correspond loosely to the relative |
69 | * weights of the colors in the NTSC grayscale equation. | 69 | * weights of the colors in the NTSC grayscale equation. |
70 | * If you want to use this code to quantize a non-RGB color space, you'll | 70 | * If you want to use this code to quantize a non-RGB color space, you'll |
71 | * probably need to change these scale factors. | 71 | * probably need to change these scale factors. |
72 | */ | 72 | */ |
73 | 73 | ||
74 | #define R_SCALE 2 /* scale R distances by this much */ | 74 | #define R_SCALE 2 /* scale R distances by this much */ |
75 | #define G_SCALE 3 /* scale G distances by this much */ | 75 | #define G_SCALE 3 /* scale G distances by this much */ |
76 | #define B_SCALE 1 /* and B by this much */ | 76 | #define B_SCALE 1 /* and B by this much */ |
77 | 77 | ||
78 | /* Relabel R/G/B as components 0/1/2, respecting the RGB ordering defined | 78 | /* Relabel R/G/B as components 0/1/2, respecting the RGB ordering defined |
79 | * in jmorecfg.h. As the code stands, it will do the right thing for R,G,B | 79 | * in jmorecfg.h. As the code stands, it will do the right thing for R,G,B |
80 | * and B,G,R orders. If you define some other weird order in jmorecfg.h, | 80 | * and B,G,R orders. If you define some other weird order in jmorecfg.h, |
81 | * you'll get compile errors until you extend this logic. In that case | 81 | * you'll get compile errors until you extend this logic. In that case |
82 | * you'll probably want to tweak the histogram sizes too. | 82 | * you'll probably want to tweak the histogram sizes too. |
83 | */ | 83 | */ |
84 | 84 | ||
85 | #if RGB_RED == 0 | 85 | #if RGB_RED == 0 |
86 | #define C0_SCALE R_SCALE | 86 | #define C0_SCALE R_SCALE |
87 | #endif | 87 | #endif |
88 | #if RGB_BLUE == 0 | 88 | #if RGB_BLUE == 0 |
89 | #define C0_SCALE B_SCALE | 89 | #define C0_SCALE B_SCALE |
90 | #endif | 90 | #endif |
91 | #if RGB_GREEN == 1 | 91 | #if RGB_GREEN == 1 |
92 | #define C1_SCALE G_SCALE | 92 | #define C1_SCALE G_SCALE |
93 | #endif | 93 | #endif |
94 | #if RGB_RED == 2 | 94 | #if RGB_RED == 2 |
95 | #define C2_SCALE R_SCALE | 95 | #define C2_SCALE R_SCALE |
96 | #endif | 96 | #endif |
97 | #if RGB_BLUE == 2 | 97 | #if RGB_BLUE == 2 |
98 | #define C2_SCALE B_SCALE | 98 | #define C2_SCALE B_SCALE |
99 | #endif | 99 | #endif |
100 | 100 | ||
101 | 101 | ||
102 | /* | 102 | /* |
103 | * First we have the histogram data structure and routines for creating it. | 103 | * First we have the histogram data structure and routines for creating it. |
104 | * | 104 | * |
105 | * The number of bits of precision can be adjusted by changing these symbols. | 105 | * The number of bits of precision can be adjusted by changing these symbols. |
106 | * We recommend keeping 6 bits for G and 5 each for R and B. | 106 | * We recommend keeping 6 bits for G and 5 each for R and B. |
107 | * If you have plenty of memory and cycles, 6 bits all around gives marginally | 107 | * If you have plenty of memory and cycles, 6 bits all around gives marginally |
108 | * better results; if you are short of memory, 5 bits all around will save | 108 | * better results; if you are short of memory, 5 bits all around will save |
109 | * some space but degrade the results. | 109 | * some space but degrade the results. |
110 | * To maintain a fully accurate histogram, we'd need to allocate a "long" | 110 | * To maintain a fully accurate histogram, we'd need to allocate a "long" |
111 | * (preferably unsigned long) for each cell. In practice this is overkill; | 111 | * (preferably unsigned long) for each cell. In practice this is overkill; |
112 | * we can get by with 16 bits per cell. Few of the cell counts will overflow, | 112 | * we can get by with 16 bits per cell. Few of the cell counts will overflow, |
113 | * and clamping those that do overflow to the maximum value will give close- | 113 | * and clamping those that do overflow to the maximum value will give close- |
114 | * enough results. This reduces the recommended histogram size from 256Kb | 114 | * enough results. This reduces the recommended histogram size from 256Kb |
115 | * to 128Kb, which is a useful savings on PC-class machines. | 115 | * to 128Kb, which is a useful savings on PC-class machines. |
116 | * (In the second pass the histogram space is re-used for pixel mapping data; | 116 | * (In the second pass the histogram space is re-used for pixel mapping data; |
117 | * in that capacity, each cell must be able to store zero to the number of | 117 | * in that capacity, each cell must be able to store zero to the number of |
118 | * desired colors. 16 bits/cell is plenty for that too.) | 118 | * desired colors. 16 bits/cell is plenty for that too.) |
119 | * Since the JPEG code is intended to run in small memory model on 80x86 | 119 | * Since the JPEG code is intended to run in small memory model on 80x86 |
120 | * machines, we can't just allocate the histogram in one chunk. Instead | 120 | * machines, we can't just allocate the histogram in one chunk. Instead |
121 | * of a true 3-D array, we use a row of pointers to 2-D arrays. Each | 121 | * of a true 3-D array, we use a row of pointers to 2-D arrays. Each |
122 | * pointer corresponds to a C0 value (typically 2^5 = 32 pointers) and | 122 | * pointer corresponds to a C0 value (typically 2^5 = 32 pointers) and |
123 | * each 2-D array has 2^6*2^5 = 2048 or 2^6*2^6 = 4096 entries. Note that | 123 | * each 2-D array has 2^6*2^5 = 2048 or 2^6*2^6 = 4096 entries. Note that |
124 | * on 80x86 machines, the pointer row is in near memory but the actual | 124 | * on 80x86 machines, the pointer row is in near memory but the actual |
125 | * arrays are in far memory (same arrangement as we use for image arrays). | 125 | * arrays are in far memory (same arrangement as we use for image arrays). |
126 | */ | 126 | */ |
127 | 127 | ||
128 | #define MAXNUMCOLORS (MAXJSAMPLE+1) /* maximum size of colormap */ | 128 | #define MAXNUMCOLORS (MAXJSAMPLE+1) /* maximum size of colormap */ |
129 | 129 | ||
130 | /* These will do the right thing for either R,G,B or B,G,R color order, | 130 | /* These will do the right thing for either R,G,B or B,G,R color order, |
131 | * but you may not like the results for other color orders. | 131 | * but you may not like the results for other color orders. |
132 | */ | 132 | */ |
133 | #define HIST_C0_BITS 5 /* bits of precision in R/B histogram */ | 133 | #define HIST_C0_BITS 5 /* bits of precision in R/B histogram */ |
134 | #define HIST_C1_BITS 6 /* bits of precision in G histogram */ | 134 | #define HIST_C1_BITS 6 /* bits of precision in G histogram */ |
135 | #define HIST_C2_BITS 5 /* bits of precision in B/R histogram */ | 135 | #define HIST_C2_BITS 5 /* bits of precision in B/R histogram */ |
136 | 136 | ||
137 | /* Number of elements along histogram axes. */ | 137 | /* Number of elements along histogram axes. */ |
138 | #define HIST_C0_ELEMS (1<<HIST_C0_BITS) | 138 | #define HIST_C0_ELEMS (1<<HIST_C0_BITS) |
139 | #define HIST_C1_ELEMS (1<<HIST_C1_BITS) | 139 | #define HIST_C1_ELEMS (1<<HIST_C1_BITS) |
140 | #define HIST_C2_ELEMS (1<<HIST_C2_BITS) | 140 | #define HIST_C2_ELEMS (1<<HIST_C2_BITS) |
141 | 141 | ||
142 | /* These are the amounts to shift an input value to get a histogram index. */ | 142 | /* These are the amounts to shift an input value to get a histogram index. */ |
143 | #define C0_SHIFT (BITS_IN_JSAMPLE-HIST_C0_BITS) | 143 | #define C0_SHIFT (BITS_IN_JSAMPLE-HIST_C0_BITS) |
144 | #define C1_SHIFT (BITS_IN_JSAMPLE-HIST_C1_BITS) | 144 | #define C1_SHIFT (BITS_IN_JSAMPLE-HIST_C1_BITS) |
145 | #define C2_SHIFT (BITS_IN_JSAMPLE-HIST_C2_BITS) | 145 | #define C2_SHIFT (BITS_IN_JSAMPLE-HIST_C2_BITS) |
146 | 146 | ||
147 | 147 | ||
148 | typedef UINT16 histcell; /* histogram cell; prefer an unsigned type */ | 148 | typedef UINT16 histcell; /* histogram cell; prefer an unsigned type */ |
149 | 149 | ||
150 | typedef histcell FAR * histptr; /* for pointers to histogram cells */ | 150 | typedef histcell FAR * histptr; /* for pointers to histogram cells */ |
151 | 151 | ||
152 | typedef histcell hist1d[HIST_C2_ELEMS]; /* typedefs for the array */ | 152 | typedef histcell hist1d[HIST_C2_ELEMS]; /* typedefs for the array */ |
153 | typedef hist1d FAR * hist2d; /* type for the 2nd-level pointers */ | 153 | typedef hist1d FAR * hist2d; /* type for the 2nd-level pointers */ |
154 | typedef hist2d * hist3d; /* type for top-level pointer */ | 154 | typedef hist2d * hist3d; /* type for top-level pointer */ |
155 | 155 | ||
156 | 156 | ||
157 | /* Declarations for Floyd-Steinberg dithering. | 157 | /* Declarations for Floyd-Steinberg dithering. |
158 | * | 158 | * |
159 | * Errors are accumulated into the array fserrors[], at a resolution of | 159 | * Errors are accumulated into the array fserrors[], at a resolution of |
160 | * 1/16th of a pixel count. The error at a given pixel is propagated | 160 | * 1/16th of a pixel count. The error at a given pixel is propagated |
161 | * to its not-yet-processed neighbors using the standard F-S fractions, | 161 | * to its not-yet-processed neighbors using the standard F-S fractions, |
162 | * ... (here) 7/16 | 162 | * ... (here) 7/16 |
163 | * 3/16 5/16 1/16 | 163 | * 3/16 5/16 1/16 |
164 | * We work left-to-right on even rows, right-to-left on odd rows. | 164 | * We work left-to-right on even rows, right-to-left on odd rows. |
165 | * | 165 | * |
166 | * We can get away with a single array (holding one row's worth of errors) | 166 | * We can get away with a single array (holding one row's worth of errors) |
167 | * by using it to store the current row's errors at pixel columns not yet | 167 | * by using it to store the current row's errors at pixel columns not yet |
168 | * processed, but the next row's errors at columns already processed. We | 168 | * processed, but the next row's errors at columns already processed. We |
169 | * need only a few extra variables to hold the errors immediately around the | 169 | * need only a few extra variables to hold the errors immediately around the |
170 | * current column. (If we are lucky, those variables are in registers, but | 170 | * current column. (If we are lucky, those variables are in registers, but |
171 | * even if not, they're probably cheaper to access than array elements are.) | 171 | * even if not, they're probably cheaper to access than array elements are.) |
172 | * | 172 | * |
173 | * The fserrors[] array has (#columns + 2) entries; the extra entry at | 173 | * The fserrors[] array has (#columns + 2) entries; the extra entry at |
174 | * each end saves us from special-casing the first and last pixels. | 174 | * each end saves us from special-casing the first and last pixels. |
175 | * Each entry is three values long, one value for each color component. | 175 | * Each entry is three values long, one value for each color component. |
176 | * | 176 | * |
177 | * Note: on a wide image, we might not have enough room in a PC's near data | 177 | * Note: on a wide image, we might not have enough room in a PC's near data |
178 | * segment to hold the error array; so it is allocated with alloc_large. | 178 | * segment to hold the error array; so it is allocated with alloc_large. |
179 | */ | 179 | */ |
180 | 180 | ||
181 | #if BITS_IN_JSAMPLE == 8 | 181 | #if BITS_IN_JSAMPLE == 8 |
182 | typedef INT16 FSERROR; /* 16 bits should be enough */ | 182 | typedef INT16 FSERROR; /* 16 bits should be enough */ |
183 | typedef int LOCFSERROR; /* use 'int' for calculation temps */ | 183 | typedef int LOCFSERROR; /* use 'int' for calculation temps */ |
184 | #else | 184 | #else |
185 | typedef INT32 FSERROR; /* may need more than 16 bits */ | 185 | typedef INT32 FSERROR; /* may need more than 16 bits */ |
186 | typedef INT32 LOCFSERROR; /* be sure calculation temps are big enough */ | 186 | typedef INT32 LOCFSERROR; /* be sure calculation temps are big enough */ |
187 | #endif | 187 | #endif |
188 | 188 | ||
189 | typedef FSERROR FAR *FSERRPTR; /* pointer to error array (in FAR storage!) */ | 189 | typedef FSERROR FAR *FSERRPTR; /* pointer to error array (in FAR storage!) */ |
190 | 190 | ||
191 | 191 | ||
192 | /* Private subobject */ | 192 | /* Private subobject */ |
193 | 193 | ||
194 | typedef struct { | 194 | typedef struct { |
195 | struct jpeg_color_quantizer pub; /* public fields */ | 195 | struct jpeg_color_quantizer pub; /* public fields */ |
196 | 196 | ||
197 | /* Space for the eventually created colormap is stashed here */ | 197 | /* Space for the eventually created colormap is stashed here */ |
198 | JSAMPARRAY sv_colormap; /* colormap allocated at init time */ | 198 | JSAMPARRAY sv_colormap; /* colormap allocated at init time */ |
199 | int desired; /* desired # of colors = size of colormap */ | 199 | int desired; /* desired # of colors = size of colormap */ |
200 | 200 | ||
201 | /* Variables for accumulating image statistics */ | 201 | /* Variables for accumulating image statistics */ |
202 | hist3d histogram; /* pointer to the histogram */ | 202 | hist3d histogram; /* pointer to the histogram */ |
203 | 203 | ||
204 | boolean needs_zeroed; /* TRUE if next pass must zero histogram */ | 204 | boolean needs_zeroed; /* TRUE if next pass must zero histogram */ |
205 | 205 | ||
206 | /* Variables for Floyd-Steinberg dithering */ | 206 | /* Variables for Floyd-Steinberg dithering */ |
207 | FSERRPTR fserrors; /* accumulated errors */ | 207 | FSERRPTR fserrors; /* accumulated errors */ |
208 | boolean on_odd_row; /* flag to remember which row we are on */ | 208 | boolean on_odd_row; /* flag to remember which row we are on */ |
209 | int * error_limiter; /* table for clamping the applied error */ | 209 | int * error_limiter; /* table for clamping the applied error */ |
210 | } my_cquantizer; | 210 | } my_cquantizer; |
211 | 211 | ||
212 | typedef my_cquantizer * my_cquantize_ptr; | 212 | typedef my_cquantizer * my_cquantize_ptr; |
213 | 213 | ||
214 | 214 | ||
215 | /* | 215 | /* |
216 | * Prescan some rows of pixels. | 216 | * Prescan some rows of pixels. |
217 | * In this module the prescan simply updates the histogram, which has been | 217 | * In this module the prescan simply updates the histogram, which has been |
218 | * initialized to zeroes by start_pass. | 218 | * initialized to zeroes by start_pass. |
219 | * An output_buf parameter is required by the method signature, but no data | 219 | * An output_buf parameter is required by the method signature, but no data |
220 | * is actually output (in fact the buffer controller is probably passing a | 220 | * is actually output (in fact the buffer controller is probably passing a |
221 | * NULL pointer). | 221 | * NULL pointer). |
222 | */ | 222 | */ |
223 | 223 | ||
224 | METHODDEF(void) | 224 | METHODDEF(void) |
225 | prescan_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf, | 225 | prescan_quantize (j_decompress_ptr cinfo, JSAMPARRAY input_buf, |
226 | JSAMPARRAY output_buf, int num_rows) | 226 | JSAMPARRAY output_buf, int num_rows) |
227 | { | 227 | { |
228 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 228 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
229 | register JSAMPROW ptr; | 229 | register JSAMPROW ptr; |
230 | register histptr histp; | 230 | register histptr histp; |
231 | register hist3d histogram = cquantize->histogram; | 231 | register hist3d histogram = cquantize->histogram; |
232 | int row; | 232 | int row; |
233 | JDIMENSION col; | 233 | JDIMENSION col; |
234 | JDIMENSION width = cinfo->output_width; | 234 | JDIMENSION width = cinfo->output_width; |
235 | 235 | ||
236 | for (row = 0; row < num_rows; row++) { | 236 | for (row = 0; row < num_rows; row++) { |
237 | ptr = input_buf[row]; | 237 | ptr = input_buf[row]; |
238 | for (col = width; col > 0; col--) { | 238 | for (col = width; col > 0; col--) { |
239 | /* get pixel value and index into the histogram */ | 239 | /* get pixel value and index into the histogram */ |
240 | histp = & histogram[GETJSAMPLE(ptr[0]) >> C0_SHIFT] | 240 | histp = & histogram[GETJSAMPLE(ptr[0]) >> C0_SHIFT] |
241 | [GETJSAMPLE(ptr[1]) >> C1_SHIFT] | 241 | [GETJSAMPLE(ptr[1]) >> C1_SHIFT] |
242 | [GETJSAMPLE(ptr[2]) >> C2_SHIFT]; | 242 | [GETJSAMPLE(ptr[2]) >> C2_SHIFT]; |
243 | /* increment, check for overflow and undo increment if so. */ | 243 | /* increment, check for overflow and undo increment if so. */ |
244 | if (++(*histp) <= 0) | 244 | if (++(*histp) <= 0) |
245 | (*histp)--; | 245 | (*histp)--; |
246 | ptr += 3; | 246 | ptr += 3; |
247 | } | 247 | } |
248 | } | 248 | } |
249 | } | 249 | } |
250 | 250 | ||
251 | 251 | ||
252 | /* | 252 | /* |
253 | * Next we have the really interesting routines: selection of a colormap | 253 | * Next we have the really interesting routines: selection of a colormap |
254 | * given the completed histogram. | 254 | * given the completed histogram. |
255 | * These routines work with a list of "boxes", each representing a rectangular | 255 | * These routines work with a list of "boxes", each representing a rectangular |
256 | * subset of the input color space (to histogram precision). | 256 | * subset of the input color space (to histogram precision). |
257 | */ | 257 | */ |
258 | 258 | ||
259 | typedef struct { | 259 | typedef struct { |
260 | /* The bounds of the box (inclusive); expressed as histogram indexes */ | 260 | /* The bounds of the box (inclusive); expressed as histogram indexes */ |
261 | int c0min, c0max; | 261 | int c0min, c0max; |
262 | int c1min, c1max; | 262 | int c1min, c1max; |
263 | int c2min, c2max; | 263 | int c2min, c2max; |
264 | /* The volume (actually 2-norm) of the box */ | 264 | /* The volume (actually 2-norm) of the box */ |
265 | INT32 volume; | 265 | INT32 volume; |
266 | /* The number of nonzero histogram cells within this box */ | 266 | /* The number of nonzero histogram cells within this box */ |
267 | long colorcount; | 267 | long colorcount; |
268 | } box; | 268 | } box; |
269 | 269 | ||
270 | typedef box * boxptr; | 270 | typedef box * boxptr; |
271 | 271 | ||
272 | 272 | ||
273 | LOCAL(boxptr) | 273 | LOCAL(boxptr) |
274 | find_biggest_color_pop (boxptr boxlist, int numboxes) | 274 | find_biggest_color_pop (boxptr boxlist, int numboxes) |
275 | /* Find the splittable box with the largest color population */ | 275 | /* Find the splittable box with the largest color population */ |
276 | /* Returns NULL if no splittable boxes remain */ | 276 | /* Returns NULL if no splittable boxes remain */ |
277 | { | 277 | { |
278 | register boxptr boxp; | 278 | register boxptr boxp; |
279 | register int i; | 279 | register int i; |
280 | register long maxc = 0; | 280 | register long maxc = 0; |
281 | boxptr which = NULL; | 281 | boxptr which = NULL; |
282 | 282 | ||
283 | for (i = 0, boxp = boxlist; i < numboxes; i++, boxp++) { | 283 | for (i = 0, boxp = boxlist; i < numboxes; i++, boxp++) { |
284 | if (boxp->colorcount > maxc && boxp->volume > 0) { | 284 | if (boxp->colorcount > maxc && boxp->volume > 0) { |
285 | which = boxp; | 285 | which = boxp; |
286 | maxc = boxp->colorcount; | 286 | maxc = boxp->colorcount; |
287 | } | 287 | } |
288 | } | 288 | } |
289 | return which; | 289 | return which; |
290 | } | 290 | } |
291 | 291 | ||
292 | 292 | ||
293 | LOCAL(boxptr) | 293 | LOCAL(boxptr) |
294 | find_biggest_volume (boxptr boxlist, int numboxes) | 294 | find_biggest_volume (boxptr boxlist, int numboxes) |
295 | /* Find the splittable box with the largest (scaled) volume */ | 295 | /* Find the splittable box with the largest (scaled) volume */ |
296 | /* Returns NULL if no splittable boxes remain */ | 296 | /* Returns NULL if no splittable boxes remain */ |
297 | { | 297 | { |
298 | register boxptr boxp; | 298 | register boxptr boxp; |
299 | register int i; | 299 | register int i; |
300 | register INT32 maxv = 0; | 300 | register INT32 maxv = 0; |
301 | boxptr which = NULL; | 301 | boxptr which = NULL; |
302 | 302 | ||
303 | for (i = 0, boxp = boxlist; i < numboxes; i++, boxp++) { | 303 | for (i = 0, boxp = boxlist; i < numboxes; i++, boxp++) { |
304 | if (boxp->volume > maxv) { | 304 | if (boxp->volume > maxv) { |
305 | which = boxp; | 305 | which = boxp; |
306 | maxv = boxp->volume; | 306 | maxv = boxp->volume; |
307 | } | 307 | } |
308 | } | 308 | } |
309 | return which; | 309 | return which; |
310 | } | 310 | } |
311 | 311 | ||
312 | 312 | ||
313 | LOCAL(void) | 313 | LOCAL(void) |
314 | update_box (j_decompress_ptr cinfo, boxptr boxp) | 314 | update_box (j_decompress_ptr cinfo, boxptr boxp) |
315 | /* Shrink the min/max bounds of a box to enclose only nonzero elements, */ | 315 | /* Shrink the min/max bounds of a box to enclose only nonzero elements, */ |
316 | /* and recompute its volume and population */ | 316 | /* and recompute its volume and population */ |
317 | { | 317 | { |
318 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 318 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
319 | hist3d histogram = cquantize->histogram; | 319 | hist3d histogram = cquantize->histogram; |
320 | histptr histp; | 320 | histptr histp; |
321 | int c0,c1,c2; | 321 | int c0,c1,c2; |
322 | int c0min,c0max,c1min,c1max,c2min,c2max; | 322 | int c0min,c0max,c1min,c1max,c2min,c2max; |
323 | INT32 dist0,dist1,dist2; | 323 | INT32 dist0,dist1,dist2; |
324 | long ccount; | 324 | long ccount; |
325 | 325 | ||
326 | c0min = boxp->c0min; c0max = boxp->c0max; | 326 | c0min = boxp->c0min; c0max = boxp->c0max; |
327 | c1min = boxp->c1min; c1max = boxp->c1max; | 327 | c1min = boxp->c1min; c1max = boxp->c1max; |
328 | c2min = boxp->c2min; c2max = boxp->c2max; | 328 | c2min = boxp->c2min; c2max = boxp->c2max; |
329 | 329 | ||
330 | if (c0max > c0min) | 330 | if (c0max > c0min) |
331 | for (c0 = c0min; c0 <= c0max; c0++) | 331 | for (c0 = c0min; c0 <= c0max; c0++) |
332 | for (c1 = c1min; c1 <= c1max; c1++) { | 332 | for (c1 = c1min; c1 <= c1max; c1++) { |
333 | histp = & histogram[c0][c1][c2min]; | 333 | histp = & histogram[c0][c1][c2min]; |
334 | for (c2 = c2min; c2 <= c2max; c2++) | 334 | for (c2 = c2min; c2 <= c2max; c2++) |
335 | if (*histp++ != 0) { | 335 | if (*histp++ != 0) { |
336 | boxp->c0min = c0min = c0; | 336 | boxp->c0min = c0min = c0; |
337 | goto have_c0min; | 337 | goto have_c0min; |
338 | } | 338 | } |
339 | } | 339 | } |
340 | have_c0min: | 340 | have_c0min: |
341 | if (c0max > c0min) | 341 | if (c0max > c0min) |
342 | for (c0 = c0max; c0 >= c0min; c0--) | 342 | for (c0 = c0max; c0 >= c0min; c0--) |
343 | for (c1 = c1min; c1 <= c1max; c1++) { | 343 | for (c1 = c1min; c1 <= c1max; c1++) { |
344 | histp = & histogram[c0][c1][c2min]; | 344 | histp = & histogram[c0][c1][c2min]; |
345 | for (c2 = c2min; c2 <= c2max; c2++) | 345 | for (c2 = c2min; c2 <= c2max; c2++) |
346 | if (*histp++ != 0) { | 346 | if (*histp++ != 0) { |
347 | boxp->c0max = c0max = c0; | 347 | boxp->c0max = c0max = c0; |
348 | goto have_c0max; | 348 | goto have_c0max; |
349 | } | 349 | } |
350 | } | 350 | } |
351 | have_c0max: | 351 | have_c0max: |
352 | if (c1max > c1min) | 352 | if (c1max > c1min) |
353 | for (c1 = c1min; c1 <= c1max; c1++) | 353 | for (c1 = c1min; c1 <= c1max; c1++) |
354 | for (c0 = c0min; c0 <= c0max; c0++) { | 354 | for (c0 = c0min; c0 <= c0max; c0++) { |
355 | histp = & histogram[c0][c1][c2min]; | 355 | histp = & histogram[c0][c1][c2min]; |
356 | for (c2 = c2min; c2 <= c2max; c2++) | 356 | for (c2 = c2min; c2 <= c2max; c2++) |
357 | if (*histp++ != 0) { | 357 | if (*histp++ != 0) { |
358 | boxp->c1min = c1min = c1; | 358 | boxp->c1min = c1min = c1; |
359 | goto have_c1min; | 359 | goto have_c1min; |
360 | } | 360 | } |
361 | } | 361 | } |
362 | have_c1min: | 362 | have_c1min: |
363 | if (c1max > c1min) | 363 | if (c1max > c1min) |
364 | for (c1 = c1max; c1 >= c1min; c1--) | 364 | for (c1 = c1max; c1 >= c1min; c1--) |
365 | for (c0 = c0min; c0 <= c0max; c0++) { | 365 | for (c0 = c0min; c0 <= c0max; c0++) { |
366 | histp = & histogram[c0][c1][c2min]; | 366 | histp = & histogram[c0][c1][c2min]; |
367 | for (c2 = c2min; c2 <= c2max; c2++) | 367 | for (c2 = c2min; c2 <= c2max; c2++) |
368 | if (*histp++ != 0) { | 368 | if (*histp++ != 0) { |
369 | boxp->c1max = c1max = c1; | 369 | boxp->c1max = c1max = c1; |
370 | goto have_c1max; | 370 | goto have_c1max; |
371 | } | 371 | } |
372 | } | 372 | } |
373 | have_c1max: | 373 | have_c1max: |
374 | if (c2max > c2min) | 374 | if (c2max > c2min) |
375 | for (c2 = c2min; c2 <= c2max; c2++) | 375 | for (c2 = c2min; c2 <= c2max; c2++) |
376 | for (c0 = c0min; c0 <= c0max; c0++) { | 376 | for (c0 = c0min; c0 <= c0max; c0++) { |
377 | histp = & histogram[c0][c1min][c2]; | 377 | histp = & histogram[c0][c1min][c2]; |
378 | for (c1 = c1min; c1 <= c1max; c1++, histp += HIST_C2_ELEMS) | 378 | for (c1 = c1min; c1 <= c1max; c1++, histp += HIST_C2_ELEMS) |
379 | if (*histp != 0) { | 379 | if (*histp != 0) { |
380 | boxp->c2min = c2min = c2; | 380 | boxp->c2min = c2min = c2; |
381 | goto have_c2min; | 381 | goto have_c2min; |
382 | } | 382 | } |
383 | } | 383 | } |
384 | have_c2min: | 384 | have_c2min: |
385 | if (c2max > c2min) | 385 | if (c2max > c2min) |
386 | for (c2 = c2max; c2 >= c2min; c2--) | 386 | for (c2 = c2max; c2 >= c2min; c2--) |
387 | for (c0 = c0min; c0 <= c0max; c0++) { | 387 | for (c0 = c0min; c0 <= c0max; c0++) { |
388 | histp = & histogram[c0][c1min][c2]; | 388 | histp = & histogram[c0][c1min][c2]; |
389 | for (c1 = c1min; c1 <= c1max; c1++, histp += HIST_C2_ELEMS) | 389 | for (c1 = c1min; c1 <= c1max; c1++, histp += HIST_C2_ELEMS) |
390 | if (*histp != 0) { | 390 | if (*histp != 0) { |
391 | boxp->c2max = c2max = c2; | 391 | boxp->c2max = c2max = c2; |
392 | goto have_c2max; | 392 | goto have_c2max; |
393 | } | 393 | } |
394 | } | 394 | } |
395 | have_c2max: | 395 | have_c2max: |
396 | 396 | ||
397 | /* Update box volume. | 397 | /* Update box volume. |
398 | * We use 2-norm rather than real volume here; this biases the method | 398 | * We use 2-norm rather than real volume here; this biases the method |
399 | * against making long narrow boxes, and it has the side benefit that | 399 | * against making long narrow boxes, and it has the side benefit that |
400 | * a box is splittable iff norm > 0. | 400 | * a box is splittable iff norm > 0. |
401 | * Since the differences are expressed in histogram-cell units, | 401 | * Since the differences are expressed in histogram-cell units, |
402 | * we have to shift back to JSAMPLE units to get consistent distances; | 402 | * we have to shift back to JSAMPLE units to get consistent distances; |
403 | * after which, we scale according to the selected distance scale factors. | 403 | * after which, we scale according to the selected distance scale factors. |
404 | */ | 404 | */ |
405 | dist0 = ((c0max - c0min) << C0_SHIFT) * C0_SCALE; | 405 | dist0 = ((c0max - c0min) << C0_SHIFT) * C0_SCALE; |
406 | dist1 = ((c1max - c1min) << C1_SHIFT) * C1_SCALE; | 406 | dist1 = ((c1max - c1min) << C1_SHIFT) * C1_SCALE; |
407 | dist2 = ((c2max - c2min) << C2_SHIFT) * C2_SCALE; | 407 | dist2 = ((c2max - c2min) << C2_SHIFT) * C2_SCALE; |
408 | boxp->volume = dist0*dist0 + dist1*dist1 + dist2*dist2; | 408 | boxp->volume = dist0*dist0 + dist1*dist1 + dist2*dist2; |
409 | 409 | ||
410 | /* Now scan remaining volume of box and compute population */ | 410 | /* Now scan remaining volume of box and compute population */ |
411 | ccount = 0; | 411 | ccount = 0; |
412 | for (c0 = c0min; c0 <= c0max; c0++) | 412 | for (c0 = c0min; c0 <= c0max; c0++) |
413 | for (c1 = c1min; c1 <= c1max; c1++) { | 413 | for (c1 = c1min; c1 <= c1max; c1++) { |
414 | histp = & histogram[c0][c1][c2min]; | 414 | histp = & histogram[c0][c1][c2min]; |
415 | for (c2 = c2min; c2 <= c2max; c2++, histp++) | 415 | for (c2 = c2min; c2 <= c2max; c2++, histp++) |
416 | if (*histp != 0) { | 416 | if (*histp != 0) { |
417 | ccount++; | 417 | ccount++; |
418 | } | 418 | } |
419 | } | 419 | } |
420 | boxp->colorcount = ccount; | 420 | boxp->colorcount = ccount; |
421 | } | 421 | } |
422 | 422 | ||
423 | 423 | ||
424 | LOCAL(int) | 424 | LOCAL(int) |
425 | median_cut (j_decompress_ptr cinfo, boxptr boxlist, int numboxes, | 425 | median_cut (j_decompress_ptr cinfo, boxptr boxlist, int numboxes, |
426 | int desired_colors) | 426 | int desired_colors) |
427 | /* Repeatedly select and split the largest box until we have enough boxes */ | 427 | /* Repeatedly select and split the largest box until we have enough boxes */ |
428 | { | 428 | { |
429 | int n,lb; | 429 | int n,lb; |
430 | int c0,c1,c2,cmax; | 430 | int c0,c1,c2,cmax; |
431 | register boxptr b1,b2; | 431 | register boxptr b1,b2; |
432 | 432 | ||
433 | while (numboxes < desired_colors) { | 433 | while (numboxes < desired_colors) { |
434 | /* Select box to split. | 434 | /* Select box to split. |
435 | * Current algorithm: by population for first half, then by volume. | 435 | * Current algorithm: by population for first half, then by volume. |
436 | */ | 436 | */ |
437 | if (numboxes*2 <= desired_colors) { | 437 | if (numboxes*2 <= desired_colors) { |
438 | b1 = find_biggest_color_pop(boxlist, numboxes); | 438 | b1 = find_biggest_color_pop(boxlist, numboxes); |
439 | } else { | 439 | } else { |
440 | b1 = find_biggest_volume(boxlist, numboxes); | 440 | b1 = find_biggest_volume(boxlist, numboxes); |
441 | } | 441 | } |
442 | if (b1 == NULL) /* no splittable boxes left! */ | 442 | if (b1 == NULL) /* no splittable boxes left! */ |
443 | break; | 443 | break; |
444 | b2 = &boxlist[numboxes]; /* where new box will go */ | 444 | b2 = &boxlist[numboxes]; /* where new box will go */ |
445 | /* Copy the color bounds to the new box. */ | 445 | /* Copy the color bounds to the new box. */ |
446 | b2->c0max = b1->c0max; b2->c1max = b1->c1max; b2->c2max = b1->c2max; | 446 | b2->c0max = b1->c0max; b2->c1max = b1->c1max; b2->c2max = b1->c2max; |
447 | b2->c0min = b1->c0min; b2->c1min = b1->c1min; b2->c2min = b1->c2min; | 447 | b2->c0min = b1->c0min; b2->c1min = b1->c1min; b2->c2min = b1->c2min; |
448 | /* Choose which axis to split the box on. | 448 | /* Choose which axis to split the box on. |
449 | * Current algorithm: longest scaled axis. | 449 | * Current algorithm: longest scaled axis. |
450 | * See notes in update_box about scaling distances. | 450 | * See notes in update_box about scaling distances. |
451 | */ | 451 | */ |
452 | c0 = ((b1->c0max - b1->c0min) << C0_SHIFT) * C0_SCALE; | 452 | c0 = ((b1->c0max - b1->c0min) << C0_SHIFT) * C0_SCALE; |
453 | c1 = ((b1->c1max - b1->c1min) << C1_SHIFT) * C1_SCALE; | 453 | c1 = ((b1->c1max - b1->c1min) << C1_SHIFT) * C1_SCALE; |
454 | c2 = ((b1->c2max - b1->c2min) << C2_SHIFT) * C2_SCALE; | 454 | c2 = ((b1->c2max - b1->c2min) << C2_SHIFT) * C2_SCALE; |
455 | /* We want to break any ties in favor of green, then red, blue last. | 455 | /* We want to break any ties in favor of green, then red, blue last. |
456 | * This code does the right thing for R,G,B or B,G,R color orders only. | 456 | * This code does the right thing for R,G,B or B,G,R color orders only. |
457 | */ | 457 | */ |
458 | #if RGB_RED == 0 | 458 | #if RGB_RED == 0 |
459 | cmax = c1; n = 1; | 459 | cmax = c1; n = 1; |
460 | if (c0 > cmax) { cmax = c0; n = 0; } | 460 | if (c0 > cmax) { cmax = c0; n = 0; } |
461 | if (c2 > cmax) { n = 2; } | 461 | if (c2 > cmax) { n = 2; } |
462 | #else | 462 | #else |
463 | cmax = c1; n = 1; | 463 | cmax = c1; n = 1; |
464 | if (c2 > cmax) { cmax = c2; n = 2; } | 464 | if (c2 > cmax) { cmax = c2; n = 2; } |
465 | if (c0 > cmax) { n = 0; } | 465 | if (c0 > cmax) { n = 0; } |
466 | #endif | 466 | #endif |
467 | /* Choose split point along selected axis, and update box bounds. | 467 | /* Choose split point along selected axis, and update box bounds. |
468 | * Current algorithm: split at halfway point. | 468 | * Current algorithm: split at halfway point. |
469 | * (Since the box has been shrunk to minimum volume, | 469 | * (Since the box has been shrunk to minimum volume, |
470 | * any split will produce two nonempty subboxes.) | 470 | * any split will produce two nonempty subboxes.) |
471 | * Note that lb value is max for lower box, so must be < old max. | 471 | * Note that lb value is max for lower box, so must be < old max. |
472 | */ | 472 | */ |
473 | switch (n) { | 473 | switch (n) { |
474 | case 0: | 474 | case 0: |
475 | lb = (b1->c0max + b1->c0min) / 2; | 475 | lb = (b1->c0max + b1->c0min) / 2; |
476 | b1->c0max = lb; | 476 | b1->c0max = lb; |
477 | b2->c0min = lb+1; | 477 | b2->c0min = lb+1; |
478 | break; | 478 | break; |
479 | case 1: | 479 | case 1: |
480 | lb = (b1->c1max + b1->c1min) / 2; | 480 | lb = (b1->c1max + b1->c1min) / 2; |
481 | b1->c1max = lb; | 481 | b1->c1max = lb; |
482 | b2->c1min = lb+1; | 482 | b2->c1min = lb+1; |
483 | break; | 483 | break; |
484 | case 2: | 484 | case 2: |
485 | lb = (b1->c2max + b1->c2min) / 2; | 485 | lb = (b1->c2max + b1->c2min) / 2; |
486 | b1->c2max = lb; | 486 | b1->c2max = lb; |
487 | b2->c2min = lb+1; | 487 | b2->c2min = lb+1; |
488 | break; | 488 | break; |
489 | } | 489 | } |
490 | /* Update stats for boxes */ | 490 | /* Update stats for boxes */ |
491 | update_box(cinfo, b1); | 491 | update_box(cinfo, b1); |
492 | update_box(cinfo, b2); | 492 | update_box(cinfo, b2); |
493 | numboxes++; | 493 | numboxes++; |
494 | } | 494 | } |
495 | return numboxes; | 495 | return numboxes; |
496 | } | 496 | } |
497 | 497 | ||
498 | 498 | ||
499 | LOCAL(void) | 499 | LOCAL(void) |
500 | compute_color (j_decompress_ptr cinfo, boxptr boxp, int icolor) | 500 | compute_color (j_decompress_ptr cinfo, boxptr boxp, int icolor) |
501 | /* Compute representative color for a box, put it in colormap[icolor] */ | 501 | /* Compute representative color for a box, put it in colormap[icolor] */ |
502 | { | 502 | { |
503 | /* Current algorithm: mean weighted by pixels (not colors) */ | 503 | /* Current algorithm: mean weighted by pixels (not colors) */ |
504 | /* Note it is important to get the rounding correct! */ | 504 | /* Note it is important to get the rounding correct! */ |
505 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 505 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
506 | hist3d histogram = cquantize->histogram; | 506 | hist3d histogram = cquantize->histogram; |
507 | histptr histp; | 507 | histptr histp; |
508 | int c0,c1,c2; | 508 | int c0,c1,c2; |
509 | int c0min,c0max,c1min,c1max,c2min,c2max; | 509 | int c0min,c0max,c1min,c1max,c2min,c2max; |
510 | long count; | 510 | long count; |
511 | long total = 0; | 511 | long total = 0; |
512 | long c0total = 0; | 512 | long c0total = 0; |
513 | long c1total = 0; | 513 | long c1total = 0; |
514 | long c2total = 0; | 514 | long c2total = 0; |
515 | 515 | ||
516 | c0min = boxp->c0min; c0max = boxp->c0max; | 516 | c0min = boxp->c0min; c0max = boxp->c0max; |
517 | c1min = boxp->c1min; c1max = boxp->c1max; | 517 | c1min = boxp->c1min; c1max = boxp->c1max; |
518 | c2min = boxp->c2min; c2max = boxp->c2max; | 518 | c2min = boxp->c2min; c2max = boxp->c2max; |
519 | 519 | ||
520 | for (c0 = c0min; c0 <= c0max; c0++) | 520 | for (c0 = c0min; c0 <= c0max; c0++) |
521 | for (c1 = c1min; c1 <= c1max; c1++) { | 521 | for (c1 = c1min; c1 <= c1max; c1++) { |
522 | histp = & histogram[c0][c1][c2min]; | 522 | histp = & histogram[c0][c1][c2min]; |
523 | for (c2 = c2min; c2 <= c2max; c2++) { | 523 | for (c2 = c2min; c2 <= c2max; c2++) { |
524 | if ((count = *histp++) != 0) { | 524 | if ((count = *histp++) != 0) { |
525 | total += count; | 525 | total += count; |
526 | c0total += ((c0 << C0_SHIFT) + ((1<<C0_SHIFT)>>1)) * count; | 526 | c0total += ((c0 << C0_SHIFT) + ((1<<C0_SHIFT)>>1)) * count; |
527 | c1total += ((c1 << C1_SHIFT) + ((1<<C1_SHIFT)>>1)) * count; | 527 | c1total += ((c1 << C1_SHIFT) + ((1<<C1_SHIFT)>>1)) * count; |
528 | c2total += ((c2 << C2_SHIFT) + ((1<<C2_SHIFT)>>1)) * count; | 528 | c2total += ((c2 << C2_SHIFT) + ((1<<C2_SHIFT)>>1)) * count; |
529 | } | 529 | } |
530 | } | 530 | } |
531 | } | 531 | } |
532 | 532 | ||
533 | cinfo->colormap[0][icolor] = (JSAMPLE) ((c0total + (total>>1)) / total); | 533 | cinfo->colormap[0][icolor] = (JSAMPLE) ((c0total + (total>>1)) / total); |
534 | cinfo->colormap[1][icolor] = (JSAMPLE) ((c1total + (total>>1)) / total); | 534 | cinfo->colormap[1][icolor] = (JSAMPLE) ((c1total + (total>>1)) / total); |
535 | cinfo->colormap[2][icolor] = (JSAMPLE) ((c2total + (total>>1)) / total); | 535 | cinfo->colormap[2][icolor] = (JSAMPLE) ((c2total + (total>>1)) / total); |
536 | } | 536 | } |
537 | 537 | ||
538 | 538 | ||
539 | LOCAL(void) | 539 | LOCAL(void) |
540 | select_colors (j_decompress_ptr cinfo, int desired_colors) | 540 | select_colors (j_decompress_ptr cinfo, int desired_colors) |
541 | /* Master routine for color selection */ | 541 | /* Master routine for color selection */ |
542 | { | 542 | { |
543 | boxptr boxlist; | 543 | boxptr boxlist; |
544 | int numboxes; | 544 | int numboxes; |
545 | int i; | 545 | int i; |
546 | 546 | ||
547 | /* Allocate workspace for box list */ | 547 | /* Allocate workspace for box list */ |
548 | boxlist = (boxptr) (*cinfo->mem->alloc_small) | 548 | boxlist = (boxptr) (*cinfo->mem->alloc_small) |
549 | ((j_common_ptr) cinfo, JPOOL_IMAGE, desired_colors * SIZEOF(box)); | 549 | ((j_common_ptr) cinfo, JPOOL_IMAGE, desired_colors * SIZEOF(box)); |
550 | /* Initialize one box containing whole space */ | 550 | /* Initialize one box containing whole space */ |
551 | numboxes = 1; | 551 | numboxes = 1; |
552 | boxlist[0].c0min = 0; | 552 | boxlist[0].c0min = 0; |
553 | boxlist[0].c0max = MAXJSAMPLE >> C0_SHIFT; | 553 | boxlist[0].c0max = MAXJSAMPLE >> C0_SHIFT; |
554 | boxlist[0].c1min = 0; | 554 | boxlist[0].c1min = 0; |
555 | boxlist[0].c1max = MAXJSAMPLE >> C1_SHIFT; | 555 | boxlist[0].c1max = MAXJSAMPLE >> C1_SHIFT; |
556 | boxlist[0].c2min = 0; | 556 | boxlist[0].c2min = 0; |
557 | boxlist[0].c2max = MAXJSAMPLE >> C2_SHIFT; | 557 | boxlist[0].c2max = MAXJSAMPLE >> C2_SHIFT; |
558 | /* Shrink it to actually-used volume and set its statistics */ | 558 | /* Shrink it to actually-used volume and set its statistics */ |
559 | update_box(cinfo, & boxlist[0]); | 559 | update_box(cinfo, & boxlist[0]); |
560 | /* Perform median-cut to produce final box list */ | 560 | /* Perform median-cut to produce final box list */ |
561 | numboxes = median_cut(cinfo, boxlist, numboxes, desired_colors); | 561 | numboxes = median_cut(cinfo, boxlist, numboxes, desired_colors); |
562 | /* Compute the representative color for each box, fill colormap */ | 562 | /* Compute the representative color for each box, fill colormap */ |
563 | for (i = 0; i < numboxes; i++) | 563 | for (i = 0; i < numboxes; i++) |
564 | compute_color(cinfo, & boxlist[i], i); | 564 | compute_color(cinfo, & boxlist[i], i); |
565 | cinfo->actual_number_of_colors = numboxes; | 565 | cinfo->actual_number_of_colors = numboxes; |
566 | TRACEMS1(cinfo, 1, JTRC_QUANT_SELECTED, numboxes); | 566 | TRACEMS1(cinfo, 1, JTRC_QUANT_SELECTED, numboxes); |
567 | } | 567 | } |
568 | 568 | ||
569 | 569 | ||
570 | /* | 570 | /* |
571 | * These routines are concerned with the time-critical task of mapping input | 571 | * These routines are concerned with the time-critical task of mapping input |
572 | * colors to the nearest color in the selected colormap. | 572 | * colors to the nearest color in the selected colormap. |
573 | * | 573 | * |
574 | * We re-use the histogram space as an "inverse color map", essentially a | 574 | * We re-use the histogram space as an "inverse color map", essentially a |
575 | * cache for the results of nearest-color searches. All colors within a | 575 | * cache for the results of nearest-color searches. All colors within a |
576 | * histogram cell will be mapped to the same colormap entry, namely the one | 576 | * histogram cell will be mapped to the same colormap entry, namely the one |
577 | * closest to the cell's center. This may not be quite the closest entry to | 577 | * closest to the cell's center. This may not be quite the closest entry to |
578 | * the actual input color, but it's almost as good. A zero in the cache | 578 | * the actual input color, but it's almost as good. A zero in the cache |
579 | * indicates we haven't found the nearest color for that cell yet; the array | 579 | * indicates we haven't found the nearest color for that cell yet; the array |
580 | * is cleared to zeroes before starting the mapping pass. When we find the | 580 | * is cleared to zeroes before starting the mapping pass. When we find the |
581 | * nearest color for a cell, its colormap index plus one is recorded in the | 581 | * nearest color for a cell, its colormap index plus one is recorded in the |
582 | * cache for future use. The pass2 scanning routines call fill_inverse_cmap | 582 | * cache for future use. The pass2 scanning routines call fill_inverse_cmap |
583 | * when they need to use an unfilled entry in the cache. | 583 | * when they need to use an unfilled entry in the cache. |
584 | * | 584 | * |
585 | * Our method of efficiently finding nearest colors is based on the "locally | 585 | * Our method of efficiently finding nearest colors is based on the "locally |
586 | * sorted search" idea described by Heckbert and on the incremental distance | 586 | * sorted search" idea described by Heckbert and on the incremental distance |
587 | * calculation described by Spencer W. Thomas in chapter III.1 of Graphics | 587 | * calculation described by Spencer W. Thomas in chapter III.1 of Graphics |
588 | * Gems II (James Arvo, ed. Academic Press, 1991). Thomas points out that | 588 | * Gems II (James Arvo, ed. Academic Press, 1991). Thomas points out that |
589 | * the distances from a given colormap entry to each cell of the histogram can | 589 | * the distances from a given colormap entry to each cell of the histogram can |
590 | * be computed quickly using an incremental method: the differences between | 590 | * be computed quickly using an incremental method: the differences between |
591 | * distances to adjacent cells themselves differ by a constant. This allows a | 591 | * distances to adjacent cells themselves differ by a constant. This allows a |
592 | * fairly fast implementation of the "brute force" approach of computing the | 592 | * fairly fast implementation of the "brute force" approach of computing the |
593 | * distance from every colormap entry to every histogram cell. Unfortunately, | 593 | * distance from every colormap entry to every histogram cell. Unfortunately, |
594 | * it needs a work array to hold the best-distance-so-far for each histogram | 594 | * it needs a work array to hold the best-distance-so-far for each histogram |
595 | * cell (because the inner loop has to be over cells, not colormap entries). | 595 | * cell (because the inner loop has to be over cells, not colormap entries). |
596 | * The work array elements have to be INT32s, so the work array would need | 596 | * The work array elements have to be INT32s, so the work array would need |
597 | * 256Kb at our recommended precision. This is not feasible in DOS machines. | 597 | * 256Kb at our recommended precision. This is not feasible in DOS machines. |
598 | * | 598 | * |
599 | * To get around these problems, we apply Thomas' method to compute the | 599 | * To get around these problems, we apply Thomas' method to compute the |
600 | * nearest colors for only the cells within a small subbox of the histogram. | 600 | * nearest colors for only the cells within a small subbox of the histogram. |
601 | * The work array need be only as big as the subbox, so the memory usage | 601 | * The work array need be only as big as the subbox, so the memory usage |
602 | * problem is solved. Furthermore, we need not fill subboxes that are never | 602 | * problem is solved. Furthermore, we need not fill subboxes that are never |
603 | * referenced in pass2; many images use only part of the color gamut, so a | 603 | * referenced in pass2; many images use only part of the color gamut, so a |
604 | * fair amount of work is saved. An additional advantage of this | 604 | * fair amount of work is saved. An additional advantage of this |
605 | * approach is that we can apply Heckbert's locality criterion to quickly | 605 | * approach is that we can apply Heckbert's locality criterion to quickly |
606 | * eliminate colormap entries that are far away from the subbox; typically | 606 | * eliminate colormap entries that are far away from the subbox; typically |
607 | * three-fourths of the colormap entries are rejected by Heckbert's criterion, | 607 | * three-fourths of the colormap entries are rejected by Heckbert's criterion, |
608 | * and we need not compute their distances to individual cells in the subbox. | 608 | * and we need not compute their distances to individual cells in the subbox. |
609 | * The speed of this approach is heavily influenced by the subbox size: too | 609 | * The speed of this approach is heavily influenced by the subbox size: too |
610 | * small means too much overhead, too big loses because Heckbert's criterion | 610 | * small means too much overhead, too big loses because Heckbert's criterion |
611 | * can't eliminate as many colormap entries. Empirically the best subbox | 611 | * can't eliminate as many colormap entries. Empirically the best subbox |
612 | * size seems to be about 1/512th of the histogram (1/8th in each direction). | 612 | * size seems to be about 1/512th of the histogram (1/8th in each direction). |
613 | * | 613 | * |
614 | * Thomas' article also describes a refined method which is asymptotically | 614 | * Thomas' article also describes a refined method which is asymptotically |
615 | * faster than the brute-force method, but it is also far more complex and | 615 | * faster than the brute-force method, but it is also far more complex and |
616 | * cannot efficiently be applied to small subboxes. It is therefore not | 616 | * cannot efficiently be applied to small subboxes. It is therefore not |
617 | * useful for programs intended to be portable to DOS machines. On machines | 617 | * useful for programs intended to be portable to DOS machines. On machines |
618 | * with plenty of memory, filling the whole histogram in one shot with Thomas' | 618 | * with plenty of memory, filling the whole histogram in one shot with Thomas' |
619 | * refined method might be faster than the present code --- but then again, | 619 | * refined method might be faster than the present code --- but then again, |
620 | * it might not be any faster, and it's certainly more complicated. | 620 | * it might not be any faster, and it's certainly more complicated. |
621 | */ | 621 | */ |
622 | 622 | ||
623 | 623 | ||
624 | /* log2(histogram cells in update box) for each axis; this can be adjusted */ | 624 | /* log2(histogram cells in update box) for each axis; this can be adjusted */ |
625 | #define BOX_C0_LOG (HIST_C0_BITS-3) | 625 | #define BOX_C0_LOG (HIST_C0_BITS-3) |
626 | #define BOX_C1_LOG (HIST_C1_BITS-3) | 626 | #define BOX_C1_LOG (HIST_C1_BITS-3) |
627 | #define BOX_C2_LOG (HIST_C2_BITS-3) | 627 | #define BOX_C2_LOG (HIST_C2_BITS-3) |
628 | 628 | ||
629 | #define BOX_C0_ELEMS (1<<BOX_C0_LOG) /* # of hist cells in update box */ | 629 | #define BOX_C0_ELEMS (1<<BOX_C0_LOG) /* # of hist cells in update box */ |
630 | #define BOX_C1_ELEMS (1<<BOX_C1_LOG) | 630 | #define BOX_C1_ELEMS (1<<BOX_C1_LOG) |
631 | #define BOX_C2_ELEMS (1<<BOX_C2_LOG) | 631 | #define BOX_C2_ELEMS (1<<BOX_C2_LOG) |
632 | 632 | ||
633 | #define BOX_C0_SHIFT (C0_SHIFT + BOX_C0_LOG) | 633 | #define BOX_C0_SHIFT (C0_SHIFT + BOX_C0_LOG) |
634 | #define BOX_C1_SHIFT (C1_SHIFT + BOX_C1_LOG) | 634 | #define BOX_C1_SHIFT (C1_SHIFT + BOX_C1_LOG) |
635 | #define BOX_C2_SHIFT (C2_SHIFT + BOX_C2_LOG) | 635 | #define BOX_C2_SHIFT (C2_SHIFT + BOX_C2_LOG) |
636 | 636 | ||
637 | 637 | ||
638 | /* | 638 | /* |
639 | * The next three routines implement inverse colormap filling. They could | 639 | * The next three routines implement inverse colormap filling. They could |
640 | * all be folded into one big routine, but splitting them up this way saves | 640 | * all be folded into one big routine, but splitting them up this way saves |
641 | * some stack space (the mindist[] and bestdist[] arrays need not coexist) | 641 | * some stack space (the mindist[] and bestdist[] arrays need not coexist) |
642 | * and may allow some compilers to produce better code by registerizing more | 642 | * and may allow some compilers to produce better code by registerizing more |
643 | * inner-loop variables. | 643 | * inner-loop variables. |
644 | */ | 644 | */ |
645 | 645 | ||
646 | LOCAL(int) | 646 | LOCAL(int) |
647 | find_nearby_colors (j_decompress_ptr cinfo, int minc0, int minc1, int minc2, | 647 | find_nearby_colors (j_decompress_ptr cinfo, int minc0, int minc1, int minc2, |
648 | JSAMPLE colorlist[]) | 648 | JSAMPLE colorlist[]) |
649 | /* Locate the colormap entries close enough to an update box to be candidates | 649 | /* Locate the colormap entries close enough to an update box to be candidates |
650 | * for the nearest entry to some cell(s) in the update box. The update box | 650 | * for the nearest entry to some cell(s) in the update box. The update box |
651 | * is specified by the center coordinates of its first cell. The number of | 651 | * is specified by the center coordinates of its first cell. The number of |
652 | * candidate colormap entries is returned, and their colormap indexes are | 652 | * candidate colormap entries is returned, and their colormap indexes are |
653 | * placed in colorlist[]. | 653 | * placed in colorlist[]. |
654 | * This routine uses Heckbert's "locally sorted search" criterion to select | 654 | * This routine uses Heckbert's "locally sorted search" criterion to select |
655 | * the colors that need further consideration. | 655 | * the colors that need further consideration. |
656 | */ | 656 | */ |
657 | { | 657 | { |
658 | int numcolors = cinfo->actual_number_of_colors; | 658 | int numcolors = cinfo->actual_number_of_colors; |
659 | int maxc0, maxc1, maxc2; | 659 | int maxc0, maxc1, maxc2; |
660 | int centerc0, centerc1, centerc2; | 660 | int centerc0, centerc1, centerc2; |
661 | int i, x, ncolors; | 661 | int i, x, ncolors; |
662 | INT32 minmaxdist, min_dist, max_dist, tdist; | 662 | INT32 minmaxdist, min_dist, max_dist, tdist; |
663 | INT32 mindist[MAXNUMCOLORS]; /* min distance to colormap entry i */ | 663 | INT32 mindist[MAXNUMCOLORS]; /* min distance to colormap entry i */ |
664 | 664 | ||
665 | /* Compute true coordinates of update box's upper corner and center. | 665 | /* Compute true coordinates of update box's upper corner and center. |
666 | * Actually we compute the coordinates of the center of the upper-corner | 666 | * Actually we compute the coordinates of the center of the upper-corner |
667 | * histogram cell, which are the upper bounds of the volume we care about. | 667 | * histogram cell, which are the upper bounds of the volume we care about. |
668 | * Note that since ">>" rounds down, the "center" values may be closer to | 668 | * Note that since ">>" rounds down, the "center" values may be closer to |
669 | * min than to max; hence comparisons to them must be "<=", not "<". | 669 | * min than to max; hence comparisons to them must be "<=", not "<". |
670 | */ | 670 | */ |
671 | maxc0 = minc0 + ((1 << BOX_C0_SHIFT) - (1 << C0_SHIFT)); | 671 | maxc0 = minc0 + ((1 << BOX_C0_SHIFT) - (1 << C0_SHIFT)); |
672 | centerc0 = (minc0 + maxc0) >> 1; | 672 | centerc0 = (minc0 + maxc0) >> 1; |
673 | maxc1 = minc1 + ((1 << BOX_C1_SHIFT) - (1 << C1_SHIFT)); | 673 | maxc1 = minc1 + ((1 << BOX_C1_SHIFT) - (1 << C1_SHIFT)); |
674 | centerc1 = (minc1 + maxc1) >> 1; | 674 | centerc1 = (minc1 + maxc1) >> 1; |
675 | maxc2 = minc2 + ((1 << BOX_C2_SHIFT) - (1 << C2_SHIFT)); | 675 | maxc2 = minc2 + ((1 << BOX_C2_SHIFT) - (1 << C2_SHIFT)); |
676 | centerc2 = (minc2 + maxc2) >> 1; | 676 | centerc2 = (minc2 + maxc2) >> 1; |
677 | 677 | ||
678 | /* For each color in colormap, find: | 678 | /* For each color in colormap, find: |
679 | * 1. its minimum squared-distance to any point in the update box | 679 | * 1. its minimum squared-distance to any point in the update box |
680 | * (zero if color is within update box); | 680 | * (zero if color is within update box); |
681 | * 2. its maximum squared-distance to any point in the update box. | 681 | * 2. its maximum squared-distance to any point in the update box. |
682 | * Both of these can be found by considering only the corners of the box. | 682 | * Both of these can be found by considering only the corners of the box. |
683 | * We save the minimum distance for each color in mindist[]; | 683 | * We save the minimum distance for each color in mindist[]; |
684 | * only the smallest maximum distance is of interest. | 684 | * only the smallest maximum distance is of interest. |
685 | */ | 685 | */ |
686 | minmaxdist = 0x7FFFFFFFL; | 686 | minmaxdist = 0x7FFFFFFFL; |
687 | 687 | ||
688 | for (i = 0; i < numcolors; i++) { | 688 | for (i = 0; i < numcolors; i++) { |
689 | /* We compute the squared-c0-distance term, then add in the other two. */ | 689 | /* We compute the squared-c0-distance term, then add in the other two. */ |
690 | x = GETJSAMPLE(cinfo->colormap[0][i]); | 690 | x = GETJSAMPLE(cinfo->colormap[0][i]); |
691 | if (x < minc0) { | 691 | if (x < minc0) { |
692 | tdist = (x - minc0) * C0_SCALE; | 692 | tdist = (x - minc0) * C0_SCALE; |
693 | min_dist = tdist*tdist; | 693 | min_dist = tdist*tdist; |
694 | tdist = (x - maxc0) * C0_SCALE; | 694 | tdist = (x - maxc0) * C0_SCALE; |
695 | max_dist = tdist*tdist; | 695 | max_dist = tdist*tdist; |
696 | } else if (x > maxc0) { | 696 | } else if (x > maxc0) { |
697 | tdist = (x - maxc0) * C0_SCALE; | 697 | tdist = (x - maxc0) * C0_SCALE; |
698 | min_dist = tdist*tdist; | 698 | min_dist = tdist*tdist; |
699 | tdist = (x - minc0) * C0_SCALE; | 699 | tdist = (x - minc0) * C0_SCALE; |
700 | max_dist = tdist*tdist; | 700 | max_dist = tdist*tdist; |
701 | } else { | 701 | } else { |
702 | /* within cell range so no contribution to min_dist */ | 702 | /* within cell range so no contribution to min_dist */ |
703 | min_dist = 0; | 703 | min_dist = 0; |
704 | if (x <= centerc0) { | 704 | if (x <= centerc0) { |
705 | tdist = (x - maxc0) * C0_SCALE; | 705 | tdist = (x - maxc0) * C0_SCALE; |
706 | max_dist = tdist*tdist; | 706 | max_dist = tdist*tdist; |
707 | } else { | 707 | } else { |
708 | tdist = (x - minc0) * C0_SCALE; | 708 | tdist = (x - minc0) * C0_SCALE; |
709 | max_dist = tdist*tdist; | 709 | max_dist = tdist*tdist; |
710 | } | 710 | } |
711 | } | 711 | } |
712 | 712 | ||
713 | x = GETJSAMPLE(cinfo->colormap[1][i]); | 713 | x = GETJSAMPLE(cinfo->colormap[1][i]); |
714 | if (x < minc1) { | 714 | if (x < minc1) { |
715 | tdist = (x - minc1) * C1_SCALE; | 715 | tdist = (x - minc1) * C1_SCALE; |
716 | min_dist += tdist*tdist; | 716 | min_dist += tdist*tdist; |
717 | tdist = (x - maxc1) * C1_SCALE; | 717 | tdist = (x - maxc1) * C1_SCALE; |
718 | max_dist += tdist*tdist; | 718 | max_dist += tdist*tdist; |
719 | } else if (x > maxc1) { | 719 | } else if (x > maxc1) { |
720 | tdist = (x - maxc1) * C1_SCALE; | 720 | tdist = (x - maxc1) * C1_SCALE; |
721 | min_dist += tdist*tdist; | 721 | min_dist += tdist*tdist; |
722 | tdist = (x - minc1) * C1_SCALE; | 722 | tdist = (x - minc1) * C1_SCALE; |
723 | max_dist += tdist*tdist; | 723 | max_dist += tdist*tdist; |
724 | } else { | 724 | } else { |
725 | /* within cell range so no contribution to min_dist */ | 725 | /* within cell range so no contribution to min_dist */ |
726 | if (x <= centerc1) { | 726 | if (x <= centerc1) { |
727 | tdist = (x - maxc1) * C1_SCALE; | 727 | tdist = (x - maxc1) * C1_SCALE; |
728 | max_dist += tdist*tdist; | 728 | max_dist += tdist*tdist; |
729 | } else { | 729 | } else { |
730 | tdist = (x - minc1) * C1_SCALE; | 730 | tdist = (x - minc1) * C1_SCALE; |
731 | max_dist += tdist*tdist; | 731 | max_dist += tdist*tdist; |
732 | } | 732 | } |
733 | } | 733 | } |
734 | 734 | ||
735 | x = GETJSAMPLE(cinfo->colormap[2][i]); | 735 | x = GETJSAMPLE(cinfo->colormap[2][i]); |
736 | if (x < minc2) { | 736 | if (x < minc2) { |
737 | tdist = (x - minc2) * C2_SCALE; | 737 | tdist = (x - minc2) * C2_SCALE; |
738 | min_dist += tdist*tdist; | 738 | min_dist += tdist*tdist; |
739 | tdist = (x - maxc2) * C2_SCALE; | 739 | tdist = (x - maxc2) * C2_SCALE; |
740 | max_dist += tdist*tdist; | 740 | max_dist += tdist*tdist; |
741 | } else if (x > maxc2) { | 741 | } else if (x > maxc2) { |
742 | tdist = (x - maxc2) * C2_SCALE; | 742 | tdist = (x - maxc2) * C2_SCALE; |
743 | min_dist += tdist*tdist; | 743 | min_dist += tdist*tdist; |
744 | tdist = (x - minc2) * C2_SCALE; | 744 | tdist = (x - minc2) * C2_SCALE; |
745 | max_dist += tdist*tdist; | 745 | max_dist += tdist*tdist; |
746 | } else { | 746 | } else { |
747 | /* within cell range so no contribution to min_dist */ | 747 | /* within cell range so no contribution to min_dist */ |
748 | if (x <= centerc2) { | 748 | if (x <= centerc2) { |
749 | tdist = (x - maxc2) * C2_SCALE; | 749 | tdist = (x - maxc2) * C2_SCALE; |
750 | max_dist += tdist*tdist; | 750 | max_dist += tdist*tdist; |
751 | } else { | 751 | } else { |
752 | tdist = (x - minc2) * C2_SCALE; | 752 | tdist = (x - minc2) * C2_SCALE; |
753 | max_dist += tdist*tdist; | 753 | max_dist += tdist*tdist; |
754 | } | 754 | } |
755 | } | 755 | } |
756 | 756 | ||
757 | mindist[i] = min_dist; /* save away the results */ | 757 | mindist[i] = min_dist; /* save away the results */ |
758 | if (max_dist < minmaxdist) | 758 | if (max_dist < minmaxdist) |
759 | minmaxdist = max_dist; | 759 | minmaxdist = max_dist; |
760 | } | 760 | } |
761 | 761 | ||
762 | /* Now we know that no cell in the update box is more than minmaxdist | 762 | /* Now we know that no cell in the update box is more than minmaxdist |
763 | * away from some colormap entry. Therefore, only colors that are | 763 | * away from some colormap entry. Therefore, only colors that are |
764 | * within minmaxdist of some part of the box need be considered. | 764 | * within minmaxdist of some part of the box need be considered. |
765 | */ | 765 | */ |
766 | ncolors = 0; | 766 | ncolors = 0; |
767 | for (i = 0; i < numcolors; i++) { | 767 | for (i = 0; i < numcolors; i++) { |
768 | if (mindist[i] <= minmaxdist) | 768 | if (mindist[i] <= minmaxdist) |
769 | colorlist[ncolors++] = (JSAMPLE) i; | 769 | colorlist[ncolors++] = (JSAMPLE) i; |
770 | } | 770 | } |
771 | return ncolors; | 771 | return ncolors; |
772 | } | 772 | } |
773 | 773 | ||
774 | 774 | ||
775 | LOCAL(void) | 775 | LOCAL(void) |
776 | find_best_colors (j_decompress_ptr cinfo, int minc0, int minc1, int minc2, | 776 | find_best_colors (j_decompress_ptr cinfo, int minc0, int minc1, int minc2, |
777 | int numcolors, JSAMPLE colorlist[], JSAMPLE bestcolor[]) | 777 | int numcolors, JSAMPLE colorlist[], JSAMPLE bestcolor[]) |
778 | /* Find the closest colormap entry for each cell in the update box, | 778 | /* Find the closest colormap entry for each cell in the update box, |
779 | * given the list of candidate colors prepared by find_nearby_colors. | 779 | * given the list of candidate colors prepared by find_nearby_colors. |
780 | * Return the indexes of the closest entries in the bestcolor[] array. | 780 | * Return the indexes of the closest entries in the bestcolor[] array. |
781 | * This routine uses Thomas' incremental distance calculation method to | 781 | * This routine uses Thomas' incremental distance calculation method to |
782 | * find the distance from a colormap entry to successive cells in the box. | 782 | * find the distance from a colormap entry to successive cells in the box. |
783 | */ | 783 | */ |
784 | { | 784 | { |
785 | int ic0, ic1, ic2; | 785 | int ic0, ic1, ic2; |
786 | int i, icolor; | 786 | int i, icolor; |
787 | register INT32 * bptr; /* pointer into bestdist[] array */ | 787 | register INT32 * bptr; /* pointer into bestdist[] array */ |
788 | JSAMPLE * cptr; /* pointer into bestcolor[] array */ | 788 | JSAMPLE * cptr; /* pointer into bestcolor[] array */ |
789 | INT32 dist0, dist1; /* initial distance values */ | 789 | INT32 dist0, dist1; /* initial distance values */ |
790 | register INT32 dist2; /* current distance in inner loop */ | 790 | register INT32 dist2; /* current distance in inner loop */ |
791 | INT32 xx0, xx1; /* distance increments */ | 791 | INT32 xx0, xx1; /* distance increments */ |
792 | register INT32 xx2; | 792 | register INT32 xx2; |
793 | INT32 inc0, inc1, inc2; /* initial values for increments */ | 793 | INT32 inc0, inc1, inc2; /* initial values for increments */ |
794 | /* This array holds the distance to the nearest-so-far color for each cell */ | 794 | /* This array holds the distance to the nearest-so-far color for each cell */ |
795 | INT32 bestdist[BOX_C0_ELEMS * BOX_C1_ELEMS * BOX_C2_ELEMS]; | 795 | INT32 bestdist[BOX_C0_ELEMS * BOX_C1_ELEMS * BOX_C2_ELEMS]; |
796 | 796 | ||
797 | /* Initialize best-distance for each cell of the update box */ | 797 | /* Initialize best-distance for each cell of the update box */ |
798 | bptr = bestdist; | 798 | bptr = bestdist; |
799 | for (i = BOX_C0_ELEMS*BOX_C1_ELEMS*BOX_C2_ELEMS-1; i >= 0; i--) | 799 | for (i = BOX_C0_ELEMS*BOX_C1_ELEMS*BOX_C2_ELEMS-1; i >= 0; i--) |
800 | *bptr++ = 0x7FFFFFFFL; | 800 | *bptr++ = 0x7FFFFFFFL; |
801 | 801 | ||
802 | /* For each color selected by find_nearby_colors, | 802 | /* For each color selected by find_nearby_colors, |
803 | * compute its distance to the center of each cell in the box. | 803 | * compute its distance to the center of each cell in the box. |
804 | * If that's less than best-so-far, update best distance and color number. | 804 | * If that's less than best-so-far, update best distance and color number. |
805 | */ | 805 | */ |
806 | 806 | ||
807 | /* Nominal steps between cell centers ("x" in Thomas article) */ | 807 | /* Nominal steps between cell centers ("x" in Thomas article) */ |
808 | #define STEP_C0 ((1 << C0_SHIFT) * C0_SCALE) | 808 | #define STEP_C0 ((1 << C0_SHIFT) * C0_SCALE) |
809 | #define STEP_C1 ((1 << C1_SHIFT) * C1_SCALE) | 809 | #define STEP_C1 ((1 << C1_SHIFT) * C1_SCALE) |
810 | #define STEP_C2 ((1 << C2_SHIFT) * C2_SCALE) | 810 | #define STEP_C2 ((1 << C2_SHIFT) * C2_SCALE) |
811 | 811 | ||
812 | for (i = 0; i < numcolors; i++) { | 812 | for (i = 0; i < numcolors; i++) { |
813 | icolor = GETJSAMPLE(colorlist[i]); | 813 | icolor = GETJSAMPLE(colorlist[i]); |
814 | /* Compute (square of) distance from minc0/c1/c2 to this color */ | 814 | /* Compute (square of) distance from minc0/c1/c2 to this color */ |
815 | inc0 = (minc0 - GETJSAMPLE(cinfo->colormap[0][icolor])) * C0_SCALE; | 815 | inc0 = (minc0 - GETJSAMPLE(cinfo->colormap[0][icolor])) * C0_SCALE; |
816 | dist0 = inc0*inc0; | 816 | dist0 = inc0*inc0; |
817 | inc1 = (minc1 - GETJSAMPLE(cinfo->colormap[1][icolor])) * C1_SCALE; | 817 | inc1 = (minc1 - GETJSAMPLE(cinfo->colormap[1][icolor])) * C1_SCALE; |
818 | dist0 += inc1*inc1; | 818 | dist0 += inc1*inc1; |
819 | inc2 = (minc2 - GETJSAMPLE(cinfo->colormap[2][icolor])) * C2_SCALE; | 819 | inc2 = (minc2 - GETJSAMPLE(cinfo->colormap[2][icolor])) * C2_SCALE; |
820 | dist0 += inc2*inc2; | 820 | dist0 += inc2*inc2; |
821 | /* Form the initial difference increments */ | 821 | /* Form the initial difference increments */ |
822 | inc0 = inc0 * (2 * STEP_C0) + STEP_C0 * STEP_C0; | 822 | inc0 = inc0 * (2 * STEP_C0) + STEP_C0 * STEP_C0; |
823 | inc1 = inc1 * (2 * STEP_C1) + STEP_C1 * STEP_C1; | 823 | inc1 = inc1 * (2 * STEP_C1) + STEP_C1 * STEP_C1; |
824 | inc2 = inc2 * (2 * STEP_C2) + STEP_C2 * STEP_C2; | 824 | inc2 = inc2 * (2 * STEP_C2) + STEP_C2 * STEP_C2; |
825 | /* Now loop over all cells in box, updating distance per Thomas method */ | 825 | /* Now loop over all cells in box, updating distance per Thomas method */ |
826 | bptr = bestdist; | 826 | bptr = bestdist; |
827 | cptr = bestcolor; | 827 | cptr = bestcolor; |
828 | xx0 = inc0; | 828 | xx0 = inc0; |
829 | for (ic0 = BOX_C0_ELEMS-1; ic0 >= 0; ic0--) { | 829 | for (ic0 = BOX_C0_ELEMS-1; ic0 >= 0; ic0--) { |
830 | dist1 = dist0; | 830 | dist1 = dist0; |
831 | xx1 = inc1; | 831 | xx1 = inc1; |
832 | for (ic1 = BOX_C1_ELEMS-1; ic1 >= 0; ic1--) { | 832 | for (ic1 = BOX_C1_ELEMS-1; ic1 >= 0; ic1--) { |
833 | dist2 = dist1; | 833 | dist2 = dist1; |
834 | xx2 = inc2; | 834 | xx2 = inc2; |
835 | for (ic2 = BOX_C2_ELEMS-1; ic2 >= 0; ic2--) { | 835 | for (ic2 = BOX_C2_ELEMS-1; ic2 >= 0; ic2--) { |
836 | if (dist2 < *bptr) { | 836 | if (dist2 < *bptr) { |
837 | *bptr = dist2; | 837 | *bptr = dist2; |
838 | *cptr = (JSAMPLE) icolor; | 838 | *cptr = (JSAMPLE) icolor; |
839 | } | 839 | } |
840 | dist2 += xx2; | 840 | dist2 += xx2; |
841 | xx2 += 2 * STEP_C2 * STEP_C2; | 841 | xx2 += 2 * STEP_C2 * STEP_C2; |
842 | bptr++; | 842 | bptr++; |
843 | cptr++; | 843 | cptr++; |
844 | } | 844 | } |
845 | dist1 += xx1; | 845 | dist1 += xx1; |
846 | xx1 += 2 * STEP_C1 * STEP_C1; | 846 | xx1 += 2 * STEP_C1 * STEP_C1; |
847 | } | 847 | } |
848 | dist0 += xx0; | 848 | dist0 += xx0; |
849 | xx0 += 2 * STEP_C0 * STEP_C0; | 849 | xx0 += 2 * STEP_C0 * STEP_C0; |
850 | } | 850 | } |
851 | } | 851 | } |
852 | } | 852 | } |
853 | 853 | ||
854 | 854 | ||
855 | LOCAL(void) | 855 | LOCAL(void) |
856 | fill_inverse_cmap (j_decompress_ptr cinfo, int c0, int c1, int c2) | 856 | fill_inverse_cmap (j_decompress_ptr cinfo, int c0, int c1, int c2) |
857 | /* Fill the inverse-colormap entries in the update box that contains */ | 857 | /* Fill the inverse-colormap entries in the update box that contains */ |
858 | /* histogram cell c0/c1/c2. (Only that one cell MUST be filled, but */ | 858 | /* histogram cell c0/c1/c2. (Only that one cell MUST be filled, but */ |
859 | /* we can fill as many others as we wish.) */ | 859 | /* we can fill as many others as we wish.) */ |
860 | { | 860 | { |
861 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 861 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
862 | hist3d histogram = cquantize->histogram; | 862 | hist3d histogram = cquantize->histogram; |
863 | int minc0, minc1, minc2; /* lower left corner of update box */ | 863 | int minc0, minc1, minc2; /* lower left corner of update box */ |
864 | int ic0, ic1, ic2; | 864 | int ic0, ic1, ic2; |
865 | register JSAMPLE * cptr; /* pointer into bestcolor[] array */ | 865 | register JSAMPLE * cptr; /* pointer into bestcolor[] array */ |
866 | register histptr cachep; /* pointer into main cache array */ | 866 | register histptr cachep; /* pointer into main cache array */ |
867 | /* This array lists the candidate colormap indexes. */ | 867 | /* This array lists the candidate colormap indexes. */ |
868 | JSAMPLE colorlist[MAXNUMCOLORS]; | 868 | JSAMPLE colorlist[MAXNUMCOLORS]; |
869 | int numcolors; /* number of candidate colors */ | 869 | int numcolors; /* number of candidate colors */ |
870 | /* This array holds the actually closest colormap index for each cell. */ | 870 | /* This array holds the actually closest colormap index for each cell. */ |
871 | JSAMPLE bestcolor[BOX_C0_ELEMS * BOX_C1_ELEMS * BOX_C2_ELEMS]; | 871 | JSAMPLE bestcolor[BOX_C0_ELEMS * BOX_C1_ELEMS * BOX_C2_ELEMS]; |
872 | 872 | ||
873 | /* Convert cell coordinates to update box ID */ | 873 | /* Convert cell coordinates to update box ID */ |
874 | c0 >>= BOX_C0_LOG; | 874 | c0 >>= BOX_C0_LOG; |
875 | c1 >>= BOX_C1_LOG; | 875 | c1 >>= BOX_C1_LOG; |
876 | c2 >>= BOX_C2_LOG; | 876 | c2 >>= BOX_C2_LOG; |
877 | 877 | ||
878 | /* Compute true coordinates of update box's origin corner. | 878 | /* Compute true coordinates of update box's origin corner. |
879 | * Actually we compute the coordinates of the center of the corner | 879 | * Actually we compute the coordinates of the center of the corner |
880 | * histogram cell, which are the lower bounds of the volume we care about. | 880 | * histogram cell, which are the lower bounds of the volume we care about. |
881 | */ | 881 | */ |
882 | minc0 = (c0 << BOX_C0_SHIFT) + ((1 << C0_SHIFT) >> 1); | 882 | minc0 = (c0 << BOX_C0_SHIFT) + ((1 << C0_SHIFT) >> 1); |
883 | minc1 = (c1 << BOX_C1_SHIFT) + ((1 << C1_SHIFT) >> 1); | 883 | minc1 = (c1 << BOX_C1_SHIFT) + ((1 << C1_SHIFT) >> 1); |
884 | minc2 = (c2 << BOX_C2_SHIFT) + ((1 << C2_SHIFT) >> 1); | 884 | minc2 = (c2 << BOX_C2_SHIFT) + ((1 << C2_SHIFT) >> 1); |
885 | 885 | ||
886 | /* Determine which colormap entries are close enough to be candidates | 886 | /* Determine which colormap entries are close enough to be candidates |
887 | * for the nearest entry to some cell in the update box. | 887 | * for the nearest entry to some cell in the update box. |
888 | */ | 888 | */ |
889 | numcolors = find_nearby_colors(cinfo, minc0, minc1, minc2, colorlist); | 889 | numcolors = find_nearby_colors(cinfo, minc0, minc1, minc2, colorlist); |
890 | 890 | ||
891 | /* Determine the actually nearest colors. */ | 891 | /* Determine the actually nearest colors. */ |
892 | find_best_colors(cinfo, minc0, minc1, minc2, numcolors, colorlist, | 892 | find_best_colors(cinfo, minc0, minc1, minc2, numcolors, colorlist, |
893 | bestcolor); | 893 | bestcolor); |
894 | 894 | ||
895 | /* Save the best color numbers (plus 1) in the main cache array */ | 895 | /* Save the best color numbers (plus 1) in the main cache array */ |
896 | c0 <<= BOX_C0_LOG; /* convert ID back to base cell indexes */ | 896 | c0 <<= BOX_C0_LOG; /* convert ID back to base cell indexes */ |
897 | c1 <<= BOX_C1_LOG; | 897 | c1 <<= BOX_C1_LOG; |
898 | c2 <<= BOX_C2_LOG; | 898 | c2 <<= BOX_C2_LOG; |
899 | cptr = bestcolor; | 899 | cptr = bestcolor; |
900 | for (ic0 = 0; ic0 < BOX_C0_ELEMS; ic0++) { | 900 | for (ic0 = 0; ic0 < BOX_C0_ELEMS; ic0++) { |
901 | for (ic1 = 0; ic1 < BOX_C1_ELEMS; ic1++) { | 901 | for (ic1 = 0; ic1 < BOX_C1_ELEMS; ic1++) { |
902 | cachep = & histogram[c0+ic0][c1+ic1][c2]; | 902 | cachep = & histogram[c0+ic0][c1+ic1][c2]; |
903 | for (ic2 = 0; ic2 < BOX_C2_ELEMS; ic2++) { | 903 | for (ic2 = 0; ic2 < BOX_C2_ELEMS; ic2++) { |
904 | *cachep++ = (histcell) (GETJSAMPLE(*cptr++) + 1); | 904 | *cachep++ = (histcell) (GETJSAMPLE(*cptr++) + 1); |
905 | } | 905 | } |
906 | } | 906 | } |
907 | } | 907 | } |
908 | } | 908 | } |
909 | 909 | ||
910 | 910 | ||
911 | /* | 911 | /* |
912 | * Map some rows of pixels to the output colormapped representation. | 912 | * Map some rows of pixels to the output colormapped representation. |
913 | */ | 913 | */ |
914 | 914 | ||
915 | METHODDEF(void) | 915 | METHODDEF(void) |
916 | pass2_no_dither (j_decompress_ptr cinfo, | 916 | pass2_no_dither (j_decompress_ptr cinfo, |
917 | JSAMPARRAY input_buf, JSAMPARRAY output_buf, int num_rows) | 917 | JSAMPARRAY input_buf, JSAMPARRAY output_buf, int num_rows) |
918 | /* This version performs no dithering */ | 918 | /* This version performs no dithering */ |
919 | { | 919 | { |
920 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 920 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
921 | hist3d histogram = cquantize->histogram; | 921 | hist3d histogram = cquantize->histogram; |
922 | register JSAMPROW inptr, outptr; | 922 | register JSAMPROW inptr, outptr; |
923 | register histptr cachep; | 923 | register histptr cachep; |
924 | register int c0, c1, c2; | 924 | register int c0, c1, c2; |
925 | int row; | 925 | int row; |
926 | JDIMENSION col; | 926 | JDIMENSION col; |
927 | JDIMENSION width = cinfo->output_width; | 927 | JDIMENSION width = cinfo->output_width; |
928 | 928 | ||
929 | for (row = 0; row < num_rows; row++) { | 929 | for (row = 0; row < num_rows; row++) { |
930 | inptr = input_buf[row]; | 930 | inptr = input_buf[row]; |
931 | outptr = output_buf[row]; | 931 | outptr = output_buf[row]; |
932 | for (col = width; col > 0; col--) { | 932 | for (col = width; col > 0; col--) { |
933 | /* get pixel value and index into the cache */ | 933 | /* get pixel value and index into the cache */ |
934 | c0 = GETJSAMPLE(*inptr++) >> C0_SHIFT; | 934 | c0 = GETJSAMPLE(*inptr++) >> C0_SHIFT; |
935 | c1 = GETJSAMPLE(*inptr++) >> C1_SHIFT; | 935 | c1 = GETJSAMPLE(*inptr++) >> C1_SHIFT; |
936 | c2 = GETJSAMPLE(*inptr++) >> C2_SHIFT; | 936 | c2 = GETJSAMPLE(*inptr++) >> C2_SHIFT; |
937 | cachep = & histogram[c0][c1][c2]; | 937 | cachep = & histogram[c0][c1][c2]; |
938 | /* If we have not seen this color before, find nearest colormap entry */ | 938 | /* If we have not seen this color before, find nearest colormap entry */ |
939 | /* and update the cache */ | 939 | /* and update the cache */ |
940 | if (*cachep == 0) | 940 | if (*cachep == 0) |
941 | fill_inverse_cmap(cinfo, c0,c1,c2); | 941 | fill_inverse_cmap(cinfo, c0,c1,c2); |
942 | /* Now emit the colormap index for this cell */ | 942 | /* Now emit the colormap index for this cell */ |
943 | *outptr++ = (JSAMPLE) (*cachep - 1); | 943 | *outptr++ = (JSAMPLE) (*cachep - 1); |
944 | } | 944 | } |
945 | } | 945 | } |
946 | } | 946 | } |
947 | 947 | ||
948 | 948 | ||
949 | METHODDEF(void) | 949 | METHODDEF(void) |
950 | pass2_fs_dither (j_decompress_ptr cinfo, | 950 | pass2_fs_dither (j_decompress_ptr cinfo, |
951 | JSAMPARRAY input_buf, JSAMPARRAY output_buf, int num_rows) | 951 | JSAMPARRAY input_buf, JSAMPARRAY output_buf, int num_rows) |
952 | /* This version performs Floyd-Steinberg dithering */ | 952 | /* This version performs Floyd-Steinberg dithering */ |
953 | { | 953 | { |
954 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 954 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
955 | hist3d histogram = cquantize->histogram; | 955 | hist3d histogram = cquantize->histogram; |
956 | register LOCFSERROR cur0, cur1, cur2; /* current error or pixel value */ | 956 | register LOCFSERROR cur0, cur1, cur2; /* current error or pixel value */ |
957 | LOCFSERROR belowerr0, belowerr1, belowerr2; /* error for pixel below cur */ | 957 | LOCFSERROR belowerr0, belowerr1, belowerr2; /* error for pixel below cur */ |
958 | LOCFSERROR bpreverr0, bpreverr1, bpreverr2; /* error for below/prev col */ | 958 | LOCFSERROR bpreverr0, bpreverr1, bpreverr2; /* error for below/prev col */ |
959 | register FSERRPTR errorptr; /* => fserrors[] at column before current */ | 959 | register FSERRPTR errorptr; /* => fserrors[] at column before current */ |
960 | JSAMPROW inptr; /* => current input pixel */ | 960 | JSAMPROW inptr; /* => current input pixel */ |
961 | JSAMPROW outptr; /* => current output pixel */ | 961 | JSAMPROW outptr; /* => current output pixel */ |
962 | histptr cachep; | 962 | histptr cachep; |
963 | int dir; /* +1 or -1 depending on direction */ | 963 | int dir; /* +1 or -1 depending on direction */ |
964 | int dir3; /* 3*dir, for advancing inptr & errorptr */ | 964 | int dir3; /* 3*dir, for advancing inptr & errorptr */ |
965 | int row; | 965 | int row; |
966 | JDIMENSION col; | 966 | JDIMENSION col; |
967 | JDIMENSION width = cinfo->output_width; | 967 | JDIMENSION width = cinfo->output_width; |
968 | JSAMPLE *range_limit = cinfo->sample_range_limit; | 968 | JSAMPLE *range_limit = cinfo->sample_range_limit; |
969 | int *error_limit = cquantize->error_limiter; | 969 | int *error_limit = cquantize->error_limiter; |
970 | JSAMPROW colormap0 = cinfo->colormap[0]; | 970 | JSAMPROW colormap0 = cinfo->colormap[0]; |
971 | JSAMPROW colormap1 = cinfo->colormap[1]; | 971 | JSAMPROW colormap1 = cinfo->colormap[1]; |
972 | JSAMPROW colormap2 = cinfo->colormap[2]; | 972 | JSAMPROW colormap2 = cinfo->colormap[2]; |
973 | SHIFT_TEMPS | 973 | SHIFT_TEMPS |
974 | 974 | ||
975 | for (row = 0; row < num_rows; row++) { | 975 | for (row = 0; row < num_rows; row++) { |
976 | inptr = input_buf[row]; | 976 | inptr = input_buf[row]; |
977 | outptr = output_buf[row]; | 977 | outptr = output_buf[row]; |
978 | if (cquantize->on_odd_row) { | 978 | if (cquantize->on_odd_row) { |
979 | /* work right to left in this row */ | 979 | /* work right to left in this row */ |
980 | inptr += (width-1) * 3; /* so point to rightmost pixel */ | 980 | inptr += (width-1) * 3; /* so point to rightmost pixel */ |
981 | outptr += width-1; | 981 | outptr += width-1; |
982 | dir = -1; | 982 | dir = -1; |
983 | dir3 = -3; | 983 | dir3 = -3; |
984 | errorptr = cquantize->fserrors + (width+1)*3; /* => entry after last column */ | 984 | errorptr = cquantize->fserrors + (width+1)*3; /* => entry after last column */ |
985 | cquantize->on_odd_row = FALSE; /* flip for next time */ | 985 | cquantize->on_odd_row = FALSE; /* flip for next time */ |
986 | } else { | 986 | } else { |
987 | /* work left to right in this row */ | 987 | /* work left to right in this row */ |
988 | dir = 1; | 988 | dir = 1; |
989 | dir3 = 3; | 989 | dir3 = 3; |
990 | errorptr = cquantize->fserrors; /* => entry before first real column */ | 990 | errorptr = cquantize->fserrors; /* => entry before first real column */ |
991 | cquantize->on_odd_row = TRUE; /* flip for next time */ | 991 | cquantize->on_odd_row = TRUE; /* flip for next time */ |
992 | } | 992 | } |
993 | /* Preset error values: no error propagated to first pixel from left */ | 993 | /* Preset error values: no error propagated to first pixel from left */ |
994 | cur0 = cur1 = cur2 = 0; | 994 | cur0 = cur1 = cur2 = 0; |
995 | /* and no error propagated to row below yet */ | 995 | /* and no error propagated to row below yet */ |
996 | belowerr0 = belowerr1 = belowerr2 = 0; | 996 | belowerr0 = belowerr1 = belowerr2 = 0; |
997 | bpreverr0 = bpreverr1 = bpreverr2 = 0; | 997 | bpreverr0 = bpreverr1 = bpreverr2 = 0; |
998 | 998 | ||
999 | for (col = width; col > 0; col--) { | 999 | for (col = width; col > 0; col--) { |
1000 | /* curN holds the error propagated from the previous pixel on the | 1000 | /* curN holds the error propagated from the previous pixel on the |
1001 | * current line. Add the error propagated from the previous line | 1001 | * current line. Add the error propagated from the previous line |
1002 | * to form the complete error correction term for this pixel, and | 1002 | * to form the complete error correction term for this pixel, and |
1003 | * round the error term (which is expressed * 16) to an integer. | 1003 | * round the error term (which is expressed * 16) to an integer. |
1004 | * RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct | 1004 | * RIGHT_SHIFT rounds towards minus infinity, so adding 8 is correct |
1005 | * for either sign of the error value. | 1005 | * for either sign of the error value. |
1006 | * Note: errorptr points to *previous* column's array entry. | 1006 | * Note: errorptr points to *previous* column's array entry. |
1007 | */ | 1007 | */ |
1008 | cur0 = RIGHT_SHIFT(cur0 + errorptr[dir3+0] + 8, 4); | 1008 | cur0 = RIGHT_SHIFT(cur0 + errorptr[dir3+0] + 8, 4); |
1009 | cur1 = RIGHT_SHIFT(cur1 + errorptr[dir3+1] + 8, 4); | 1009 | cur1 = RIGHT_SHIFT(cur1 + errorptr[dir3+1] + 8, 4); |
1010 | cur2 = RIGHT_SHIFT(cur2 + errorptr[dir3+2] + 8, 4); | 1010 | cur2 = RIGHT_SHIFT(cur2 + errorptr[dir3+2] + 8, 4); |
1011 | /* Limit the error using transfer function set by init_error_limit. | 1011 | /* Limit the error using transfer function set by init_error_limit. |
1012 | * See comments with init_error_limit for rationale. | 1012 | * See comments with init_error_limit for rationale. |
1013 | */ | 1013 | */ |
1014 | cur0 = error_limit[cur0]; | 1014 | cur0 = error_limit[cur0]; |
1015 | cur1 = error_limit[cur1]; | 1015 | cur1 = error_limit[cur1]; |
1016 | cur2 = error_limit[cur2]; | 1016 | cur2 = error_limit[cur2]; |
1017 | /* Form pixel value + error, and range-limit to 0..MAXJSAMPLE. | 1017 | /* Form pixel value + error, and range-limit to 0..MAXJSAMPLE. |
1018 | * The maximum error is +- MAXJSAMPLE (or less with error limiting); | 1018 | * The maximum error is +- MAXJSAMPLE (or less with error limiting); |
1019 | * this sets the required size of the range_limit array. | 1019 | * this sets the required size of the range_limit array. |
1020 | */ | 1020 | */ |
1021 | cur0 += GETJSAMPLE(inptr[0]); | 1021 | cur0 += GETJSAMPLE(inptr[0]); |
1022 | cur1 += GETJSAMPLE(inptr[1]); | 1022 | cur1 += GETJSAMPLE(inptr[1]); |
1023 | cur2 += GETJSAMPLE(inptr[2]); | 1023 | cur2 += GETJSAMPLE(inptr[2]); |
1024 | cur0 = GETJSAMPLE(range_limit[cur0]); | 1024 | cur0 = GETJSAMPLE(range_limit[cur0]); |
1025 | cur1 = GETJSAMPLE(range_limit[cur1]); | 1025 | cur1 = GETJSAMPLE(range_limit[cur1]); |
1026 | cur2 = GETJSAMPLE(range_limit[cur2]); | 1026 | cur2 = GETJSAMPLE(range_limit[cur2]); |
1027 | /* Index into the cache with adjusted pixel value */ | 1027 | /* Index into the cache with adjusted pixel value */ |
1028 | cachep = & histogram[cur0>>C0_SHIFT][cur1>>C1_SHIFT][cur2>>C2_SHIFT]; | 1028 | cachep = & histogram[cur0>>C0_SHIFT][cur1>>C1_SHIFT][cur2>>C2_SHIFT]; |
1029 | /* If we have not seen this color before, find nearest colormap */ | 1029 | /* If we have not seen this color before, find nearest colormap */ |
1030 | /* entry and update the cache */ | 1030 | /* entry and update the cache */ |
1031 | if (*cachep == 0) | 1031 | if (*cachep == 0) |
1032 | fill_inverse_cmap(cinfo, cur0>>C0_SHIFT,cur1>>C1_SHIFT,cur2>>C2_SHIFT); | 1032 | fill_inverse_cmap(cinfo, cur0>>C0_SHIFT,cur1>>C1_SHIFT,cur2>>C2_SHIFT); |
1033 | /* Now emit the colormap index for this cell */ | 1033 | /* Now emit the colormap index for this cell */ |
1034 | { register int pixcode = *cachep - 1; | 1034 | { register int pixcode = *cachep - 1; |
1035 | *outptr = (JSAMPLE) pixcode; | 1035 | *outptr = (JSAMPLE) pixcode; |
1036 | /* Compute representation error for this pixel */ | 1036 | /* Compute representation error for this pixel */ |
1037 | cur0 -= GETJSAMPLE(colormap0[pixcode]); | 1037 | cur0 -= GETJSAMPLE(colormap0[pixcode]); |
1038 | cur1 -= GETJSAMPLE(colormap1[pixcode]); | 1038 | cur1 -= GETJSAMPLE(colormap1[pixcode]); |
1039 | cur2 -= GETJSAMPLE(colormap2[pixcode]); | 1039 | cur2 -= GETJSAMPLE(colormap2[pixcode]); |
1040 | } | 1040 | } |
1041 | /* Compute error fractions to be propagated to adjacent pixels. | 1041 | /* Compute error fractions to be propagated to adjacent pixels. |
1042 | * Add these into the running sums, and simultaneously shift the | 1042 | * Add these into the running sums, and simultaneously shift the |
1043 | * next-line error sums left by 1 column. | 1043 | * next-line error sums left by 1 column. |
1044 | */ | 1044 | */ |
1045 | { register LOCFSERROR bnexterr, delta; | 1045 | { register LOCFSERROR bnexterr, delta; |
1046 | 1046 | ||
1047 | bnexterr = cur0; /* Process component 0 */ | 1047 | bnexterr = cur0; /* Process component 0 */ |
1048 | delta = cur0 * 2; | 1048 | delta = cur0 * 2; |
1049 | cur0 += delta; /* form error * 3 */ | 1049 | cur0 += delta; /* form error * 3 */ |
1050 | errorptr[0] = (FSERROR) (bpreverr0 + cur0); | 1050 | errorptr[0] = (FSERROR) (bpreverr0 + cur0); |
1051 | cur0 += delta; /* form error * 5 */ | 1051 | cur0 += delta; /* form error * 5 */ |
1052 | bpreverr0 = belowerr0 + cur0; | 1052 | bpreverr0 = belowerr0 + cur0; |
1053 | belowerr0 = bnexterr; | 1053 | belowerr0 = bnexterr; |
1054 | cur0 += delta; /* form error * 7 */ | 1054 | cur0 += delta; /* form error * 7 */ |
1055 | bnexterr = cur1; /* Process component 1 */ | 1055 | bnexterr = cur1; /* Process component 1 */ |
1056 | delta = cur1 * 2; | 1056 | delta = cur1 * 2; |
1057 | cur1 += delta; /* form error * 3 */ | 1057 | cur1 += delta; /* form error * 3 */ |
1058 | errorptr[1] = (FSERROR) (bpreverr1 + cur1); | 1058 | errorptr[1] = (FSERROR) (bpreverr1 + cur1); |
1059 | cur1 += delta; /* form error * 5 */ | 1059 | cur1 += delta; /* form error * 5 */ |
1060 | bpreverr1 = belowerr1 + cur1; | 1060 | bpreverr1 = belowerr1 + cur1; |
1061 | belowerr1 = bnexterr; | 1061 | belowerr1 = bnexterr; |
1062 | cur1 += delta; /* form error * 7 */ | 1062 | cur1 += delta; /* form error * 7 */ |
1063 | bnexterr = cur2; /* Process component 2 */ | 1063 | bnexterr = cur2; /* Process component 2 */ |
1064 | delta = cur2 * 2; | 1064 | delta = cur2 * 2; |
1065 | cur2 += delta; /* form error * 3 */ | 1065 | cur2 += delta; /* form error * 3 */ |
1066 | errorptr[2] = (FSERROR) (bpreverr2 + cur2); | 1066 | errorptr[2] = (FSERROR) (bpreverr2 + cur2); |
1067 | cur2 += delta; /* form error * 5 */ | 1067 | cur2 += delta; /* form error * 5 */ |
1068 | bpreverr2 = belowerr2 + cur2; | 1068 | bpreverr2 = belowerr2 + cur2; |
1069 | belowerr2 = bnexterr; | 1069 | belowerr2 = bnexterr; |
1070 | cur2 += delta; /* form error * 7 */ | 1070 | cur2 += delta; /* form error * 7 */ |
1071 | } | 1071 | } |
1072 | /* At this point curN contains the 7/16 error value to be propagated | 1072 | /* At this point curN contains the 7/16 error value to be propagated |
1073 | * to the next pixel on the current line, and all the errors for the | 1073 | * to the next pixel on the current line, and all the errors for the |
1074 | * next line have been shifted over. We are therefore ready to move on. | 1074 | * next line have been shifted over. We are therefore ready to move on. |
1075 | */ | 1075 | */ |
1076 | inptr += dir3; /* Advance pixel pointers to next column */ | 1076 | inptr += dir3; /* Advance pixel pointers to next column */ |
1077 | outptr += dir; | 1077 | outptr += dir; |
1078 | errorptr += dir3; /* advance errorptr to current column */ | 1078 | errorptr += dir3; /* advance errorptr to current column */ |
1079 | } | 1079 | } |
1080 | /* Post-loop cleanup: we must unload the final error values into the | 1080 | /* Post-loop cleanup: we must unload the final error values into the |
1081 | * final fserrors[] entry. Note we need not unload belowerrN because | 1081 | * final fserrors[] entry. Note we need not unload belowerrN because |
1082 | * it is for the dummy column before or after the actual array. | 1082 | * it is for the dummy column before or after the actual array. |
1083 | */ | 1083 | */ |
1084 | errorptr[0] = (FSERROR) bpreverr0; /* unload prev errs into array */ | 1084 | errorptr[0] = (FSERROR) bpreverr0; /* unload prev errs into array */ |
1085 | errorptr[1] = (FSERROR) bpreverr1; | 1085 | errorptr[1] = (FSERROR) bpreverr1; |
1086 | errorptr[2] = (FSERROR) bpreverr2; | 1086 | errorptr[2] = (FSERROR) bpreverr2; |
1087 | } | 1087 | } |
1088 | } | 1088 | } |
1089 | 1089 | ||
1090 | 1090 | ||
1091 | /* | 1091 | /* |
1092 | * Initialize the error-limiting transfer function (lookup table). | 1092 | * Initialize the error-limiting transfer function (lookup table). |
1093 | * The raw F-S error computation can potentially compute error values of up to | 1093 | * The raw F-S error computation can potentially compute error values of up to |
1094 | * +- MAXJSAMPLE. But we want the maximum correction applied to a pixel to be | 1094 | * +- MAXJSAMPLE. But we want the maximum correction applied to a pixel to be |
1095 | * much less, otherwise obviously wrong pixels will be created. (Typical | 1095 | * much less, otherwise obviously wrong pixels will be created. (Typical |
1096 | * effects include weird fringes at color-area boundaries, isolated bright | 1096 | * effects include weird fringes at color-area boundaries, isolated bright |
1097 | * pixels in a dark area, etc.) The standard advice for avoiding this problem | 1097 | * pixels in a dark area, etc.) The standard advice for avoiding this problem |
1098 | * is to ensure that the "corners" of the color cube are allocated as output | 1098 | * is to ensure that the "corners" of the color cube are allocated as output |
1099 | * colors; then repeated errors in the same direction cannot cause cascading | 1099 | * colors; then repeated errors in the same direction cannot cause cascading |
1100 | * error buildup. However, that only prevents the error from getting | 1100 | * error buildup. However, that only prevents the error from getting |
1101 | * completely out of hand; Aaron Giles reports that error limiting improves | 1101 | * completely out of hand; Aaron Giles reports that error limiting improves |
1102 | * the results even with corner colors allocated. | 1102 | * the results even with corner colors allocated. |
1103 | * A simple clamping of the error values to about +- MAXJSAMPLE/8 works pretty | 1103 | * A simple clamping of the error values to about +- MAXJSAMPLE/8 works pretty |
1104 | * well, but the smoother transfer function used below is even better. Thanks | 1104 | * well, but the smoother transfer function used below is even better. Thanks |
1105 | * to Aaron Giles for this idea. | 1105 | * to Aaron Giles for this idea. |
1106 | */ | 1106 | */ |
1107 | 1107 | ||
1108 | LOCAL(void) | 1108 | LOCAL(void) |
1109 | init_error_limit (j_decompress_ptr cinfo) | 1109 | init_error_limit (j_decompress_ptr cinfo) |
1110 | /* Allocate and fill in the error_limiter table */ | 1110 | /* Allocate and fill in the error_limiter table */ |
1111 | { | 1111 | { |
1112 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 1112 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
1113 | int * table; | 1113 | int * table; |
1114 | int in, out; | 1114 | int in, out; |
1115 | 1115 | ||
1116 | table = (int *) (*cinfo->mem->alloc_small) | 1116 | table = (int *) (*cinfo->mem->alloc_small) |
1117 | ((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE*2+1) * SIZEOF(int)); | 1117 | ((j_common_ptr) cinfo, JPOOL_IMAGE, (MAXJSAMPLE*2+1) * SIZEOF(int)); |
1118 | table += MAXJSAMPLE; /* so can index -MAXJSAMPLE .. +MAXJSAMPLE */ | 1118 | table += MAXJSAMPLE; /* so can index -MAXJSAMPLE .. +MAXJSAMPLE */ |
1119 | cquantize->error_limiter = table; | 1119 | cquantize->error_limiter = table; |
1120 | 1120 | ||
1121 | #define STEPSIZE ((MAXJSAMPLE+1)/16) | 1121 | #define STEPSIZE ((MAXJSAMPLE+1)/16) |
1122 | /* Map errors 1:1 up to +- MAXJSAMPLE/16 */ | 1122 | /* Map errors 1:1 up to +- MAXJSAMPLE/16 */ |
1123 | out = 0; | 1123 | out = 0; |
1124 | for (in = 0; in < STEPSIZE; in++, out++) { | 1124 | for (in = 0; in < STEPSIZE; in++, out++) { |
1125 | table[in] = out; table[-in] = -out; | 1125 | table[in] = out; table[-in] = -out; |
1126 | } | 1126 | } |
1127 | /* Map errors 1:2 up to +- 3*MAXJSAMPLE/16 */ | 1127 | /* Map errors 1:2 up to +- 3*MAXJSAMPLE/16 */ |
1128 | for (; in < STEPSIZE*3; in++, out += (in&1) ? 0 : 1) { | 1128 | for (; in < STEPSIZE*3; in++, out += (in&1) ? 0 : 1) { |
1129 | table[in] = out; table[-in] = -out; | 1129 | table[in] = out; table[-in] = -out; |
1130 | } | 1130 | } |
1131 | /* Clamp the rest to final out value (which is (MAXJSAMPLE+1)/8) */ | 1131 | /* Clamp the rest to final out value (which is (MAXJSAMPLE+1)/8) */ |
1132 | for (; in <= MAXJSAMPLE; in++) { | 1132 | for (; in <= MAXJSAMPLE; in++) { |
1133 | table[in] = out; table[-in] = -out; | 1133 | table[in] = out; table[-in] = -out; |
1134 | } | 1134 | } |
1135 | #undef STEPSIZE | 1135 | #undef STEPSIZE |
1136 | } | 1136 | } |
1137 | 1137 | ||
1138 | 1138 | ||
1139 | /* | 1139 | /* |
1140 | * Finish up at the end of each pass. | 1140 | * Finish up at the end of each pass. |
1141 | */ | 1141 | */ |
1142 | 1142 | ||
1143 | METHODDEF(void) | 1143 | METHODDEF(void) |
1144 | finish_pass1 (j_decompress_ptr cinfo) | 1144 | finish_pass1 (j_decompress_ptr cinfo) |
1145 | { | 1145 | { |
1146 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 1146 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
1147 | 1147 | ||
1148 | /* Select the representative colors and fill in cinfo->colormap */ | 1148 | /* Select the representative colors and fill in cinfo->colormap */ |
1149 | cinfo->colormap = cquantize->sv_colormap; | 1149 | cinfo->colormap = cquantize->sv_colormap; |
1150 | select_colors(cinfo, cquantize->desired); | 1150 | select_colors(cinfo, cquantize->desired); |
1151 | /* Force next pass to zero the color index table */ | 1151 | /* Force next pass to zero the color index table */ |
1152 | cquantize->needs_zeroed = TRUE; | 1152 | cquantize->needs_zeroed = TRUE; |
1153 | } | 1153 | } |
1154 | 1154 | ||
1155 | 1155 | ||
1156 | METHODDEF(void) | 1156 | METHODDEF(void) |
1157 | finish_pass2 (j_decompress_ptr cinfo) | 1157 | finish_pass2 (j_decompress_ptr cinfo) |
1158 | { | 1158 | { |
1159 | /* no work */ | 1159 | /* no work */ |
1160 | } | 1160 | } |
1161 | 1161 | ||
1162 | 1162 | ||
1163 | /* | 1163 | /* |
1164 | * Initialize for each processing pass. | 1164 | * Initialize for each processing pass. |
1165 | */ | 1165 | */ |
1166 | 1166 | ||
1167 | METHODDEF(void) | 1167 | METHODDEF(void) |
1168 | start_pass_2_quant (j_decompress_ptr cinfo, boolean is_pre_scan) | 1168 | start_pass_2_quant (j_decompress_ptr cinfo, boolean is_pre_scan) |
1169 | { | 1169 | { |
1170 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 1170 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
1171 | hist3d histogram = cquantize->histogram; | 1171 | hist3d histogram = cquantize->histogram; |
1172 | int i; | 1172 | int i; |
1173 | 1173 | ||
1174 | /* Only F-S dithering or no dithering is supported. */ | 1174 | /* Only F-S dithering or no dithering is supported. */ |
1175 | /* If user asks for ordered dither, give him F-S. */ | 1175 | /* If user asks for ordered dither, give him F-S. */ |
1176 | if (cinfo->dither_mode != JDITHER_NONE) | 1176 | if (cinfo->dither_mode != JDITHER_NONE) |
1177 | cinfo->dither_mode = JDITHER_FS; | 1177 | cinfo->dither_mode = JDITHER_FS; |
1178 | 1178 | ||
1179 | if (is_pre_scan) { | 1179 | if (is_pre_scan) { |
1180 | /* Set up method pointers */ | 1180 | /* Set up method pointers */ |
1181 | cquantize->pub.color_quantize = prescan_quantize; | 1181 | cquantize->pub.color_quantize = prescan_quantize; |
1182 | cquantize->pub.finish_pass = finish_pass1; | 1182 | cquantize->pub.finish_pass = finish_pass1; |
1183 | cquantize->needs_zeroed = TRUE; /* Always zero histogram */ | 1183 | cquantize->needs_zeroed = TRUE; /* Always zero histogram */ |
1184 | } else { | 1184 | } else { |
1185 | /* Set up method pointers */ | 1185 | /* Set up method pointers */ |
1186 | if (cinfo->dither_mode == JDITHER_FS) | 1186 | if (cinfo->dither_mode == JDITHER_FS) |
1187 | cquantize->pub.color_quantize = pass2_fs_dither; | 1187 | cquantize->pub.color_quantize = pass2_fs_dither; |
1188 | else | 1188 | else |
1189 | cquantize->pub.color_quantize = pass2_no_dither; | 1189 | cquantize->pub.color_quantize = pass2_no_dither; |
1190 | cquantize->pub.finish_pass = finish_pass2; | 1190 | cquantize->pub.finish_pass = finish_pass2; |
1191 | 1191 | ||
1192 | /* Make sure color count is acceptable */ | 1192 | /* Make sure color count is acceptable */ |
1193 | i = cinfo->actual_number_of_colors; | 1193 | i = cinfo->actual_number_of_colors; |
1194 | if (i < 1) | 1194 | if (i < 1) |
1195 | ERREXIT1(cinfo, JERR_QUANT_FEW_COLORS, 1); | 1195 | ERREXIT1(cinfo, JERR_QUANT_FEW_COLORS, 1); |
1196 | if (i > MAXNUMCOLORS) | 1196 | if (i > MAXNUMCOLORS) |
1197 | ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, MAXNUMCOLORS); | 1197 | ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, MAXNUMCOLORS); |
1198 | 1198 | ||
1199 | if (cinfo->dither_mode == JDITHER_FS) { | 1199 | if (cinfo->dither_mode == JDITHER_FS) { |
1200 | size_t arraysize = (size_t) ((cinfo->output_width + 2) * | 1200 | size_t arraysize = (size_t) ((cinfo->output_width + 2) * |
1201 | (3 * SIZEOF(FSERROR))); | 1201 | (3 * SIZEOF(FSERROR))); |
1202 | /* Allocate Floyd-Steinberg workspace if we didn't already. */ | 1202 | /* Allocate Floyd-Steinberg workspace if we didn't already. */ |
1203 | if (cquantize->fserrors == NULL) | 1203 | if (cquantize->fserrors == NULL) |
1204 | cquantize->fserrors = (FSERRPTR) (*cinfo->mem->alloc_large) | 1204 | cquantize->fserrors = (FSERRPTR) (*cinfo->mem->alloc_large) |
1205 | ((j_common_ptr) cinfo, JPOOL_IMAGE, arraysize); | 1205 | ((j_common_ptr) cinfo, JPOOL_IMAGE, arraysize); |
1206 | /* Initialize the propagated errors to zero. */ | 1206 | /* Initialize the propagated errors to zero. */ |
1207 | FMEMZERO((void FAR *) cquantize->fserrors, arraysize); | 1207 | FMEMZERO((void FAR *) cquantize->fserrors, arraysize); |
1208 | /* Make the error-limit table if we didn't already. */ | 1208 | /* Make the error-limit table if we didn't already. */ |
1209 | if (cquantize->error_limiter == NULL) | 1209 | if (cquantize->error_limiter == NULL) |
1210 | init_error_limit(cinfo); | 1210 | init_error_limit(cinfo); |
1211 | cquantize->on_odd_row = FALSE; | 1211 | cquantize->on_odd_row = FALSE; |
1212 | } | 1212 | } |
1213 | 1213 | ||
1214 | } | 1214 | } |
1215 | /* Zero the histogram or inverse color map, if necessary */ | 1215 | /* Zero the histogram or inverse color map, if necessary */ |
1216 | if (cquantize->needs_zeroed) { | 1216 | if (cquantize->needs_zeroed) { |
1217 | for (i = 0; i < HIST_C0_ELEMS; i++) { | 1217 | for (i = 0; i < HIST_C0_ELEMS; i++) { |
1218 | FMEMZERO((void FAR *) histogram[i], | 1218 | FMEMZERO((void FAR *) histogram[i], |
1219 | HIST_C1_ELEMS*HIST_C2_ELEMS * SIZEOF(histcell)); | 1219 | HIST_C1_ELEMS*HIST_C2_ELEMS * SIZEOF(histcell)); |
1220 | } | 1220 | } |
1221 | cquantize->needs_zeroed = FALSE; | 1221 | cquantize->needs_zeroed = FALSE; |
1222 | } | 1222 | } |
1223 | } | 1223 | } |
1224 | 1224 | ||
1225 | 1225 | ||
1226 | /* | 1226 | /* |
1227 | * Switch to a new external colormap between output passes. | 1227 | * Switch to a new external colormap between output passes. |
1228 | */ | 1228 | */ |
1229 | 1229 | ||
1230 | METHODDEF(void) | 1230 | METHODDEF(void) |
1231 | new_color_map_2_quant (j_decompress_ptr cinfo) | 1231 | new_color_map_2_quant (j_decompress_ptr cinfo) |
1232 | { | 1232 | { |
1233 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; | 1233 | my_cquantize_ptr cquantize = (my_cquantize_ptr) cinfo->cquantize; |
1234 | 1234 | ||
1235 | /* Reset the inverse color map */ | 1235 | /* Reset the inverse color map */ |
1236 | cquantize->needs_zeroed = TRUE; | 1236 | cquantize->needs_zeroed = TRUE; |
1237 | } | 1237 | } |
1238 | 1238 | ||
1239 | 1239 | ||
1240 | /* | 1240 | /* |
1241 | * Module initialization routine for 2-pass color quantization. | 1241 | * Module initialization routine for 2-pass color quantization. |
1242 | */ | 1242 | */ |
1243 | 1243 | ||
1244 | GLOBAL(void) | 1244 | GLOBAL(void) |
1245 | jinit_2pass_quantizer (j_decompress_ptr cinfo) | 1245 | jinit_2pass_quantizer (j_decompress_ptr cinfo) |
1246 | { | 1246 | { |
1247 | my_cquantize_ptr cquantize; | 1247 | my_cquantize_ptr cquantize; |
1248 | int i; | 1248 | int i; |
1249 | 1249 | ||
1250 | cquantize = (my_cquantize_ptr) | 1250 | cquantize = (my_cquantize_ptr) |
1251 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | 1251 | (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, |
1252 | SIZEOF(my_cquantizer)); | 1252 | SIZEOF(my_cquantizer)); |
1253 | cinfo->cquantize = (struct jpeg_color_quantizer *) cquantize; | 1253 | cinfo->cquantize = (struct jpeg_color_quantizer *) cquantize; |
1254 | cquantize->pub.start_pass = start_pass_2_quant; | 1254 | cquantize->pub.start_pass = start_pass_2_quant; |
1255 | cquantize->pub.new_color_map = new_color_map_2_quant; | 1255 | cquantize->pub.new_color_map = new_color_map_2_quant; |
1256 | cquantize->fserrors = NULL; /* flag optional arrays not allocated */ | 1256 | cquantize->fserrors = NULL; /* flag optional arrays not allocated */ |
1257 | cquantize->error_limiter = NULL; | 1257 | cquantize->error_limiter = NULL; |
1258 | 1258 | ||
1259 | /* Make sure jdmaster didn't give me a case I can't handle */ | 1259 | /* Make sure jdmaster didn't give me a case I can't handle */ |
1260 | if (cinfo->out_color_components != 3) | 1260 | if (cinfo->out_color_components != 3) |
1261 | ERREXIT(cinfo, JERR_NOTIMPL); | 1261 | ERREXIT(cinfo, JERR_NOTIMPL); |
1262 | 1262 | ||
1263 | /* Allocate the histogram/inverse colormap storage */ | 1263 | /* Allocate the histogram/inverse colormap storage */ |
1264 | cquantize->histogram = (hist3d) (*cinfo->mem->alloc_small) | 1264 | cquantize->histogram = (hist3d) (*cinfo->mem->alloc_small) |
1265 | ((j_common_ptr) cinfo, JPOOL_IMAGE, HIST_C0_ELEMS * SIZEOF(hist2d)); | 1265 | ((j_common_ptr) cinfo, JPOOL_IMAGE, HIST_C0_ELEMS * SIZEOF(hist2d)); |
1266 | for (i = 0; i < HIST_C0_ELEMS; i++) { | 1266 | for (i = 0; i < HIST_C0_ELEMS; i++) { |
1267 | cquantize->histogram[i] = (hist2d) (*cinfo->mem->alloc_large) | 1267 | cquantize->histogram[i] = (hist2d) (*cinfo->mem->alloc_large) |
1268 | ((j_common_ptr) cinfo, JPOOL_IMAGE, | 1268 | ((j_common_ptr) cinfo, JPOOL_IMAGE, |
1269 | HIST_C1_ELEMS*HIST_C2_ELEMS * SIZEOF(histcell)); | 1269 | HIST_C1_ELEMS*HIST_C2_ELEMS * SIZEOF(histcell)); |
1270 | } | 1270 | } |
1271 | cquantize->needs_zeroed = TRUE; /* histogram is garbage now */ | 1271 | cquantize->needs_zeroed = TRUE; /* histogram is garbage now */ |
1272 | 1272 | ||
1273 | /* Allocate storage for the completed colormap, if required. | 1273 | /* Allocate storage for the completed colormap, if required. |
1274 | * We do this now since it is FAR storage and may affect | 1274 | * We do this now since it is FAR storage and may affect |
1275 | * the memory manager's space calculations. | 1275 | * the memory manager's space calculations. |
1276 | */ | 1276 | */ |
1277 | if (cinfo->enable_2pass_quant) { | 1277 | if (cinfo->enable_2pass_quant) { |
1278 | /* Make sure color count is acceptable */ | 1278 | /* Make sure color count is acceptable */ |
1279 | int desired = cinfo->desired_number_of_colors; | 1279 | int desired = cinfo->desired_number_of_colors; |
1280 | /* Lower bound on # of colors ... somewhat arbitrary as long as > 0 */ | 1280 | /* Lower bound on # of colors ... somewhat arbitrary as long as > 0 */ |
1281 | if (desired < 8) | 1281 | if (desired < 8) |
1282 | ERREXIT1(cinfo, JERR_QUANT_FEW_COLORS, 8); | 1282 | ERREXIT1(cinfo, JERR_QUANT_FEW_COLORS, 8); |
1283 | /* Make sure colormap indexes can be represented by JSAMPLEs */ | 1283 | /* Make sure colormap indexes can be represented by JSAMPLEs */ |
1284 | if (desired > MAXNUMCOLORS) | 1284 | if (desired > MAXNUMCOLORS) |
1285 | ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, MAXNUMCOLORS); | 1285 | ERREXIT1(cinfo, JERR_QUANT_MANY_COLORS, MAXNUMCOLORS); |
1286 | cquantize->sv_colormap = (*cinfo->mem->alloc_sarray) | 1286 | cquantize->sv_colormap = (*cinfo->mem->alloc_sarray) |
1287 | ((j_common_ptr) cinfo,JPOOL_IMAGE, (JDIMENSION) desired, (JDIMENSION) 3); | 1287 | ((j_common_ptr) cinfo,JPOOL_IMAGE, (JDIMENSION) desired, (JDIMENSION) 3); |
1288 | cquantize->desired = desired; | 1288 | cquantize->desired = desired; |
1289 | } else | 1289 | } else |
1290 | cquantize->sv_colormap = NULL; | 1290 | cquantize->sv_colormap = NULL; |
1291 | 1291 | ||
1292 | /* Only F-S dithering or no dithering is supported. */ | 1292 | /* Only F-S dithering or no dithering is supported. */ |
1293 | /* If user asks for ordered dither, give him F-S. */ | 1293 | /* If user asks for ordered dither, give him F-S. */ |
1294 | if (cinfo->dither_mode != JDITHER_NONE) | 1294 | if (cinfo->dither_mode != JDITHER_NONE) |
1295 | cinfo->dither_mode = JDITHER_FS; | 1295 | cinfo->dither_mode = JDITHER_FS; |
1296 | 1296 | ||
1297 | /* Allocate Floyd-Steinberg workspace if necessary. | 1297 | /* Allocate Floyd-Steinberg workspace if necessary. |
1298 | * This isn't really needed until pass 2, but again it is FAR storage. | 1298 | * This isn't really needed until pass 2, but again it is FAR storage. |
1299 | * Although we will cope with a later change in dither_mode, | 1299 | * Although we will cope with a later change in dither_mode, |
1300 | * we do not promise to honor max_memory_to_use if dither_mode changes. | 1300 | * we do not promise to honor max_memory_to_use if dither_mode changes. |
1301 | */ | 1301 | */ |
1302 | if (cinfo->dither_mode == JDITHER_FS) { | 1302 | if (cinfo->dither_mode == JDITHER_FS) { |
1303 | cquantize->fserrors = (FSERRPTR) (*cinfo->mem->alloc_large) | 1303 | cquantize->fserrors = (FSERRPTR) (*cinfo->mem->alloc_large) |
1304 | ((j_common_ptr) cinfo, JPOOL_IMAGE, | 1304 | ((j_common_ptr) cinfo, JPOOL_IMAGE, |
1305 | (size_t) ((cinfo->output_width + 2) * (3 * SIZEOF(FSERROR)))); | 1305 | (size_t) ((cinfo->output_width + 2) * (3 * SIZEOF(FSERROR)))); |
1306 | /* Might as well create the error-limiting table too. */ | 1306 | /* Might as well create the error-limiting table too. */ |
1307 | init_error_limit(cinfo); | 1307 | init_error_limit(cinfo); |
1308 | } | 1308 | } |
1309 | } | 1309 | } |
1310 | 1310 | ||
1311 | #endif /* QUANT_2PASS_SUPPORTED */ | 1311 | #endif /* QUANT_2PASS_SUPPORTED */ |