diff options
author | David Walter Seikel | 2013-01-13 17:24:39 +1000 |
---|---|---|
committer | David Walter Seikel | 2013-01-13 17:24:39 +1000 |
commit | 393b5cd1dc438872af89d334ef6e5fcc59f27d47 (patch) | |
tree | 6a14521219942a08a1b95cb2f5a923a9edd60f63 /libraries/irrlicht-1.8/source/Irrlicht/jpeglib/djpeg.1 | |
parent | Add a note about rasters suggested start up code. (diff) | |
download | SledjHamr-393b5cd1dc438872af89d334ef6e5fcc59f27d47.zip SledjHamr-393b5cd1dc438872af89d334ef6e5fcc59f27d47.tar.gz SledjHamr-393b5cd1dc438872af89d334ef6e5fcc59f27d47.tar.bz2 SledjHamr-393b5cd1dc438872af89d334ef6e5fcc59f27d47.tar.xz |
Added Irrlicht 1.8, but without all the Windows binaries.
Diffstat (limited to 'libraries/irrlicht-1.8/source/Irrlicht/jpeglib/djpeg.1')
-rw-r--r-- | libraries/irrlicht-1.8/source/Irrlicht/jpeglib/djpeg.1 | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/djpeg.1 b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/djpeg.1 new file mode 100644 index 0000000..9f7038f --- /dev/null +++ b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/djpeg.1 | |||
@@ -0,0 +1,252 @@ | |||
1 | .TH DJPEG 1 "3 October 2009" | ||
2 | .SH NAME | ||
3 | djpeg \- decompress a JPEG file to an image file | ||
4 | .SH SYNOPSIS | ||
5 | .B djpeg | ||
6 | [ | ||
7 | .I options | ||
8 | ] | ||
9 | [ | ||
10 | .I filename | ||
11 | ] | ||
12 | .LP | ||
13 | .SH DESCRIPTION | ||
14 | .LP | ||
15 | .B djpeg | ||
16 | decompresses the named JPEG file, or the standard input if no file is named, | ||
17 | and produces an image file on the standard output. PBMPLUS (PPM/PGM), BMP, | ||
18 | GIF, Targa, or RLE (Utah Raster Toolkit) output format can be selected. | ||
19 | (RLE is supported only if the URT library is available.) | ||
20 | .SH OPTIONS | ||
21 | All switch names may be abbreviated; for example, | ||
22 | .B \-grayscale | ||
23 | may be written | ||
24 | .B \-gray | ||
25 | or | ||
26 | .BR \-gr . | ||
27 | Most of the "basic" switches can be abbreviated to as little as one letter. | ||
28 | Upper and lower case are equivalent (thus | ||
29 | .B \-BMP | ||
30 | is the same as | ||
31 | .BR \-bmp ). | ||
32 | British spellings are also accepted (e.g., | ||
33 | .BR \-greyscale ), | ||
34 | though for brevity these are not mentioned below. | ||
35 | .PP | ||
36 | The basic switches are: | ||
37 | .TP | ||
38 | .BI \-colors " N" | ||
39 | Reduce image to at most N colors. This reduces the number of colors used in | ||
40 | the output image, so that it can be displayed on a colormapped display or | ||
41 | stored in a colormapped file format. For example, if you have an 8-bit | ||
42 | display, you'd need to reduce to 256 or fewer colors. | ||
43 | .TP | ||
44 | .BI \-quantize " N" | ||
45 | Same as | ||
46 | .BR \-colors . | ||
47 | .B \-colors | ||
48 | is the recommended name, | ||
49 | .B \-quantize | ||
50 | is provided only for backwards compatibility. | ||
51 | .TP | ||
52 | .B \-fast | ||
53 | Select recommended processing options for fast, low quality output. (The | ||
54 | default options are chosen for highest quality output.) Currently, this is | ||
55 | equivalent to \fB\-dct fast \-nosmooth \-onepass \-dither ordered\fR. | ||
56 | .TP | ||
57 | .B \-grayscale | ||
58 | Force gray-scale output even if JPEG file is color. Useful for viewing on | ||
59 | monochrome displays; also, | ||
60 | .B djpeg | ||
61 | runs noticeably faster in this mode. | ||
62 | .TP | ||
63 | .BI \-scale " M/N" | ||
64 | Scale the output image by a factor M/N. Currently supported scale factors are | ||
65 | M/N with all M from 1 to 16, where N is the source DCT size, which is 8 for | ||
66 | baseline JPEG. If the /N part is omitted, then M specifies the DCT scaled | ||
67 | size to be applied on the given input. For baseline JPEG this is equivalent | ||
68 | to M/8 scaling, since the source DCT size for baseline JPEG is 8. | ||
69 | Scaling is handy if the image is larger than your screen; also, | ||
70 | .B djpeg | ||
71 | runs much faster when scaling down the output. | ||
72 | .TP | ||
73 | .B \-bmp | ||
74 | Select BMP output format (Windows flavor). 8-bit colormapped format is | ||
75 | emitted if | ||
76 | .B \-colors | ||
77 | or | ||
78 | .B \-grayscale | ||
79 | is specified, or if the JPEG file is gray-scale; otherwise, 24-bit full-color | ||
80 | format is emitted. | ||
81 | .TP | ||
82 | .B \-gif | ||
83 | Select GIF output format. Since GIF does not support more than 256 colors, | ||
84 | .B \-colors 256 | ||
85 | is assumed (unless you specify a smaller number of colors). | ||
86 | .TP | ||
87 | .B \-os2 | ||
88 | Select BMP output format (OS/2 1.x flavor). 8-bit colormapped format is | ||
89 | emitted if | ||
90 | .B \-colors | ||
91 | or | ||
92 | .B \-grayscale | ||
93 | is specified, or if the JPEG file is gray-scale; otherwise, 24-bit full-color | ||
94 | format is emitted. | ||
95 | .TP | ||
96 | .B \-pnm | ||
97 | Select PBMPLUS (PPM/PGM) output format (this is the default format). | ||
98 | PGM is emitted if the JPEG file is gray-scale or if | ||
99 | .B \-grayscale | ||
100 | is specified; otherwise PPM is emitted. | ||
101 | .TP | ||
102 | .B \-rle | ||
103 | Select RLE output format. (Requires URT library.) | ||
104 | .TP | ||
105 | .B \-targa | ||
106 | Select Targa output format. Gray-scale format is emitted if the JPEG file is | ||
107 | gray-scale or if | ||
108 | .B \-grayscale | ||
109 | is specified; otherwise, colormapped format is emitted if | ||
110 | .B \-colors | ||
111 | is specified; otherwise, 24-bit full-color format is emitted. | ||
112 | .PP | ||
113 | Switches for advanced users: | ||
114 | .TP | ||
115 | .B \-dct int | ||
116 | Use integer DCT method (default). | ||
117 | .TP | ||
118 | .B \-dct fast | ||
119 | Use fast integer DCT (less accurate). | ||
120 | .TP | ||
121 | .B \-dct float | ||
122 | Use floating-point DCT method. | ||
123 | The float method is very slightly more accurate than the int method, but is | ||
124 | much slower unless your machine has very fast floating-point hardware. Also | ||
125 | note that results of the floating-point method may vary slightly across | ||
126 | machines, while the integer methods should give the same results everywhere. | ||
127 | The fast integer method is much less accurate than the other two. | ||
128 | .TP | ||
129 | .B \-dither fs | ||
130 | Use Floyd-Steinberg dithering in color quantization. | ||
131 | .TP | ||
132 | .B \-dither ordered | ||
133 | Use ordered dithering in color quantization. | ||
134 | .TP | ||
135 | .B \-dither none | ||
136 | Do not use dithering in color quantization. | ||
137 | By default, Floyd-Steinberg dithering is applied when quantizing colors; this | ||
138 | is slow but usually produces the best results. Ordered dither is a compromise | ||
139 | between speed and quality; no dithering is fast but usually looks awful. Note | ||
140 | that these switches have no effect unless color quantization is being done. | ||
141 | Ordered dither is only available in | ||
142 | .B \-onepass | ||
143 | mode. | ||
144 | .TP | ||
145 | .BI \-map " file" | ||
146 | Quantize to the colors used in the specified image file. This is useful for | ||
147 | producing multiple files with identical color maps, or for forcing a | ||
148 | predefined set of colors to be used. The | ||
149 | .I file | ||
150 | must be a GIF or PPM file. This option overrides | ||
151 | .B \-colors | ||
152 | and | ||
153 | .BR \-onepass . | ||
154 | .TP | ||
155 | .B \-nosmooth | ||
156 | Don't use high-quality upsampling. | ||
157 | .TP | ||
158 | .B \-onepass | ||
159 | Use one-pass instead of two-pass color quantization. The one-pass method is | ||
160 | faster and needs less memory, but it produces a lower-quality image. | ||
161 | .B \-onepass | ||
162 | is ignored unless you also say | ||
163 | .B \-colors | ||
164 | .IR N . | ||
165 | Also, the one-pass method is always used for gray-scale output (the two-pass | ||
166 | method is no improvement then). | ||
167 | .TP | ||
168 | .BI \-maxmemory " N" | ||
169 | Set limit for amount of memory to use in processing large images. Value is | ||
170 | in thousands of bytes, or millions of bytes if "M" is attached to the | ||
171 | number. For example, | ||
172 | .B \-max 4m | ||
173 | selects 4000000 bytes. If more space is needed, temporary files will be used. | ||
174 | .TP | ||
175 | .BI \-outfile " name" | ||
176 | Send output image to the named file, not to standard output. | ||
177 | .TP | ||
178 | .B \-verbose | ||
179 | Enable debug printout. More | ||
180 | .BR \-v 's | ||
181 | give more output. Also, version information is printed at startup. | ||
182 | .TP | ||
183 | .B \-debug | ||
184 | Same as | ||
185 | .BR \-verbose . | ||
186 | .SH EXAMPLES | ||
187 | .LP | ||
188 | This example decompresses the JPEG file foo.jpg, quantizes it to | ||
189 | 256 colors, and saves the output in 8-bit BMP format in foo.bmp: | ||
190 | .IP | ||
191 | .B djpeg \-colors 256 \-bmp | ||
192 | .I foo.jpg | ||
193 | .B > | ||
194 | .I foo.bmp | ||
195 | .SH HINTS | ||
196 | To get a quick preview of an image, use the | ||
197 | .B \-grayscale | ||
198 | and/or | ||
199 | .B \-scale | ||
200 | switches. | ||
201 | .B \-grayscale \-scale 1/8 | ||
202 | is the fastest case. | ||
203 | .PP | ||
204 | Several options are available that trade off image quality to gain speed. | ||
205 | .B \-fast | ||
206 | turns on the recommended settings. | ||
207 | .PP | ||
208 | .B \-dct fast | ||
209 | and/or | ||
210 | .B \-nosmooth | ||
211 | gain speed at a small sacrifice in quality. | ||
212 | When producing a color-quantized image, | ||
213 | .B \-onepass \-dither ordered | ||
214 | is fast but much lower quality than the default behavior. | ||
215 | .B \-dither none | ||
216 | may give acceptable results in two-pass mode, but is seldom tolerable in | ||
217 | one-pass mode. | ||
218 | .PP | ||
219 | If you are fortunate enough to have very fast floating point hardware, | ||
220 | \fB\-dct float\fR may be even faster than \fB\-dct fast\fR. But on most | ||
221 | machines \fB\-dct float\fR is slower than \fB\-dct int\fR; in this case it is | ||
222 | not worth using, because its theoretical accuracy advantage is too small to be | ||
223 | significant in practice. | ||
224 | .SH ENVIRONMENT | ||
225 | .TP | ||
226 | .B JPEGMEM | ||
227 | If this environment variable is set, its value is the default memory limit. | ||
228 | The value is specified as described for the | ||
229 | .B \-maxmemory | ||
230 | switch. | ||
231 | .B JPEGMEM | ||
232 | overrides the default value specified when the program was compiled, and | ||
233 | itself is overridden by an explicit | ||
234 | .BR \-maxmemory . | ||
235 | .SH SEE ALSO | ||
236 | .BR cjpeg (1), | ||
237 | .BR jpegtran (1), | ||
238 | .BR rdjpgcom (1), | ||
239 | .BR wrjpgcom (1) | ||
240 | .br | ||
241 | .BR ppm (5), | ||
242 | .BR pgm (5) | ||
243 | .br | ||
244 | Wallace, Gregory K. "The JPEG Still Picture Compression Standard", | ||
245 | Communications of the ACM, April 1991 (vol. 34, no. 4), pp. 30-44. | ||
246 | .SH AUTHOR | ||
247 | Independent JPEG Group | ||
248 | .SH BUGS | ||
249 | To avoid the Unisys LZW patent, | ||
250 | .B djpeg | ||
251 | produces uncompressed GIF files. These are larger than they should be, but | ||
252 | are readable by standard GIF decoders. | ||