1 |
greg |
2.1 |
#ifndef lint |
2 |
schorsch |
2.11 |
static const char RCSid[] = "$Id: ra_gif.c,v 2.10 2003/07/27 22:12:03 schorsch Exp $"; |
3 |
greg |
2.1 |
#endif |
4 |
|
|
/* |
5 |
|
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* Convert from Radiance picture file to Compuserve GIF. |
6 |
|
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* Currently, we don't know how to get back. |
7 |
|
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*/ |
8 |
|
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|
9 |
|
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#include <stdio.h> |
10 |
greg |
2.7 |
#include <time.h> |
11 |
schorsch |
2.8 |
#include <math.h> |
12 |
greg |
2.1 |
|
13 |
schorsch |
2.8 |
#include "platform.h" |
14 |
greg |
2.1 |
#include "color.h" |
15 |
|
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#include "resolu.h" |
16 |
schorsch |
2.11 |
#include "clrtab.h" |
17 |
greg |
2.1 |
|
18 |
|
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#define MAXCOLORS 256 |
19 |
|
|
|
20 |
|
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int rmap[MAXCOLORS]; |
21 |
|
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int gmap[MAXCOLORS]; |
22 |
|
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int bmap[MAXCOLORS]; |
23 |
|
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|
24 |
|
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int currow; |
25 |
|
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long picstart; |
26 |
greg |
2.4 |
BYTE clrtab[256][3]; |
27 |
greg |
2.1 |
|
28 |
greg |
2.4 |
extern int samplefac; |
29 |
|
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|
30 |
greg |
2.1 |
|
31 |
|
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COLR *scanln; |
32 |
greg |
2.2 |
BYTE *pixscan; |
33 |
greg |
2.1 |
|
34 |
|
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int xmax, ymax; /* picture size */ |
35 |
|
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double gamv = 2.2; /* gamma correction */ |
36 |
|
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int greyscale = 0; /* convert to B&W? */ |
37 |
greg |
2.2 |
int dither = 1; /* dither colors? */ |
38 |
greg |
2.1 |
int bradj = 0; /* brightness adjustment */ |
39 |
greg |
2.6 |
int ncolors = 0; /* number of colors requested */ |
40 |
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|
41 |
greg |
2.1 |
char *progname; |
42 |
|
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|
43 |
schorsch |
2.11 |
typedef int ifun_t(int x, int y); /* required by the GIF code below */ |
44 |
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|
45 |
|
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static void getrow(int y); |
46 |
|
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static void mkclrmap(int nc); |
47 |
|
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static void mkgrymap(int nc); |
48 |
|
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static ifun_t getgifpix; |
49 |
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|
50 |
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static void GIFEncode(FILE *fp, int GWidth, int GHeight, int GInterlace, |
51 |
|
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int Background, int BitsPerPixel, int Red[], int Green[], int Blue[], |
52 |
|
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ifun_t* GetPixel); |
53 |
greg |
2.1 |
|
54 |
schorsch |
2.11 |
|
55 |
|
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int |
56 |
|
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main(int argc, char *argv[]) |
57 |
greg |
2.1 |
{ |
58 |
|
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int bitsperpix; |
59 |
|
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int i; |
60 |
schorsch |
2.8 |
SET_DEFAULT_BINARY(); |
61 |
|
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SET_FILE_BINARY(stdin); |
62 |
|
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SET_FILE_BINARY(stdout); |
63 |
greg |
2.1 |
progname = argv[0]; |
64 |
greg |
2.4 |
samplefac = 0; |
65 |
greg |
2.1 |
|
66 |
|
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for (i = 1; i < argc; i++) |
67 |
|
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if (argv[i][0] == '-') |
68 |
|
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switch (argv[i][1]) { |
69 |
|
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case 'g': |
70 |
|
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gamv = atof(argv[++i]); |
71 |
|
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break; |
72 |
|
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case 'b': |
73 |
|
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greyscale = 1; |
74 |
|
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break; |
75 |
greg |
2.2 |
case 'd': |
76 |
|
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dither = !dither; |
77 |
|
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break; |
78 |
greg |
2.1 |
case 'c': |
79 |
|
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ncolors = atoi(argv[++i]); |
80 |
|
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break; |
81 |
|
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case 'e': |
82 |
|
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if (argv[i+1][0] != '+' && argv[i+1][0] != '-') |
83 |
|
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goto userr; |
84 |
|
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bradj = atoi(argv[++i]); |
85 |
|
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break; |
86 |
greg |
2.4 |
case 'n': |
87 |
|
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samplefac = atoi(argv[++i]); |
88 |
|
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break; |
89 |
greg |
2.1 |
default: |
90 |
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goto userr; |
91 |
|
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} |
92 |
|
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else |
93 |
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break; |
94 |
|
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|
95 |
|
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if (i < argc-2) |
96 |
|
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goto userr; |
97 |
|
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if (i <= argc-1 && freopen(argv[i], "r", stdin) == NULL) { |
98 |
|
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fprintf(stderr, "%s: cannot open input \"%s\"\n", |
99 |
|
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progname, argv[i]); |
100 |
|
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exit(1); |
101 |
|
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} |
102 |
|
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if (i == argc-2 && freopen(argv[i+1], "w", stdout) == NULL) { |
103 |
|
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fprintf(stderr, "%s: cannot open output \"%s\"\n", |
104 |
|
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progname, argv[i+1]); |
105 |
|
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exit(1); |
106 |
|
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} |
107 |
|
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if (checkheader(stdin, COLRFMT, NULL) < 0 || |
108 |
|
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fgetresolu(&xmax, &ymax, stdin) < 0) { |
109 |
|
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fprintf(stderr, "%s: bad picture format\n", progname); |
110 |
|
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exit(1); |
111 |
|
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} |
112 |
|
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picstart = ftell(stdin); |
113 |
|
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currow = -1; |
114 |
|
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scanln = (COLR *)malloc(xmax*sizeof(COLR)); |
115 |
|
|
if (scanln == NULL) { |
116 |
|
|
fprintf(stderr, "%s: out of memory\n", progname); |
117 |
|
|
exit(1); |
118 |
|
|
} |
119 |
|
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/* set up gamma correction */ |
120 |
|
|
setcolrgam(gamv); |
121 |
|
|
/* figure out the bits per pixel */ |
122 |
schorsch |
2.10 |
if ((ncolors < 2) | (ncolors > MAXCOLORS)) |
123 |
greg |
2.1 |
ncolors = MAXCOLORS; |
124 |
|
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for (bitsperpix = 1; ncolors > 1<<bitsperpix; bitsperpix++) |
125 |
|
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; |
126 |
|
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/* compute color map */ |
127 |
|
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if (greyscale) |
128 |
|
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mkgrymap(ncolors); |
129 |
|
|
else |
130 |
|
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mkclrmap(ncolors); |
131 |
|
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/* convert image */ |
132 |
|
|
GIFEncode(stdout, xmax, ymax, 0, 0, bitsperpix, |
133 |
|
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rmap, gmap, bmap, getgifpix); |
134 |
|
|
exit(0); |
135 |
|
|
userr: |
136 |
|
|
fprintf(stderr, |
137 |
greg |
2.5 |
"Usage: %s [-b][-d][-n samp][-c ncolors][-g gamv][-e +/-stops] input [output]\n", |
138 |
greg |
2.1 |
progname); |
139 |
|
|
exit(1); |
140 |
|
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} |
141 |
|
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|
142 |
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|
143 |
schorsch |
2.11 |
static void |
144 |
|
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getrow( /* get the specified row from our image */ |
145 |
|
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int y |
146 |
|
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) |
147 |
greg |
2.1 |
{ |
148 |
|
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if (y == currow) |
149 |
|
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return; |
150 |
|
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if (y < currow) { |
151 |
|
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fseek(stdin, picstart, 0); |
152 |
|
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currow = -1; |
153 |
|
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} |
154 |
|
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do |
155 |
|
|
if (freadcolrs(scanln, xmax, stdin) < 0) { |
156 |
|
|
fprintf(stderr, "%s: error reading picture (y==%d)\n", |
157 |
|
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progname, ymax-1-y); |
158 |
greg |
2.3 |
exit(1); |
159 |
greg |
2.1 |
} |
160 |
|
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while (++currow < y); |
161 |
|
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if (bradj) |
162 |
|
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shiftcolrs(scanln, xmax, bradj); |
163 |
|
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colrs_gambs(scanln, xmax); |
164 |
schorsch |
2.9 |
if (pixscan != NULL) { |
165 |
greg |
2.4 |
if (samplefac) |
166 |
|
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neu_dith_colrs(pixscan, scanln, xmax); |
167 |
|
|
else |
168 |
|
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dith_colrs(pixscan, scanln, xmax); |
169 |
schorsch |
2.9 |
} |
170 |
greg |
2.1 |
} |
171 |
|
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|
172 |
|
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|
173 |
schorsch |
2.11 |
static void |
174 |
|
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mkclrmap( /* make our color map */ |
175 |
|
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int nc |
176 |
|
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) |
177 |
greg |
2.1 |
{ |
178 |
|
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register int i; |
179 |
|
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|
180 |
greg |
2.4 |
if ((samplefac ? neu_init(xmax*ymax) : new_histo(xmax*ymax)) == -1) |
181 |
|
|
goto memerr; |
182 |
greg |
2.1 |
for (i = 0; i < ymax; i++) { |
183 |
|
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getrow(i); |
184 |
greg |
2.4 |
if (samplefac) |
185 |
|
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neu_colrs(scanln, xmax); |
186 |
|
|
else |
187 |
|
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cnt_colrs(scanln, xmax); |
188 |
greg |
2.1 |
} |
189 |
greg |
2.4 |
if (samplefac) |
190 |
|
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neu_clrtab(nc); |
191 |
|
|
else |
192 |
|
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new_clrtab(nc); |
193 |
greg |
2.1 |
for (i = 0; i < nc; i++) { |
194 |
|
|
rmap[i] = clrtab[i][RED]; |
195 |
|
|
gmap[i] = clrtab[i][GRN]; |
196 |
|
|
bmap[i] = clrtab[i][BLU]; |
197 |
|
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} |
198 |
greg |
2.4 |
if (dither && (pixscan = (BYTE *)malloc(xmax)) == NULL) |
199 |
|
|
goto memerr; |
200 |
|
|
return; |
201 |
|
|
memerr: |
202 |
|
|
fprintf(stderr, "%s: out of memory\n", progname); |
203 |
|
|
exit(1); |
204 |
greg |
2.1 |
} |
205 |
|
|
|
206 |
|
|
|
207 |
schorsch |
2.11 |
static void |
208 |
|
|
mkgrymap( |
209 |
|
|
int nc |
210 |
|
|
) |
211 |
greg |
2.1 |
{ |
212 |
|
|
register int i; |
213 |
|
|
|
214 |
|
|
for (i = 0; i < nc; i++) { |
215 |
|
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rmap[i] = |
216 |
|
|
gmap[i] = |
217 |
|
|
bmap[i] = ((unsigned)i<<8)/nc; |
218 |
|
|
} |
219 |
|
|
} |
220 |
|
|
|
221 |
|
|
|
222 |
schorsch |
2.11 |
static int |
223 |
|
|
getgifpix( /* get a single pixel from our picture */ |
224 |
|
|
int x, |
225 |
|
|
int y |
226 |
|
|
) |
227 |
greg |
2.1 |
{ |
228 |
|
|
getrow(y); |
229 |
|
|
if (greyscale) |
230 |
greg |
2.6 |
return((normbright(scanln[x])*ncolors)>>8); |
231 |
greg |
2.2 |
if (pixscan != NULL) |
232 |
|
|
return(pixscan[x]); |
233 |
greg |
2.4 |
return(samplefac ? neu_map_pixel(scanln[x]) : map_pixel(scanln[x])); |
234 |
greg |
2.1 |
} |
235 |
|
|
|
236 |
|
|
|
237 |
|
|
/* |
238 |
|
|
* SCARY GIF code follows . . . . sorry. |
239 |
|
|
* |
240 |
|
|
* Based on GIFENCOD by David Rowley <[email protected]>.A |
241 |
schorsch |
2.11 |
* Lempel-Ziv compression based on "compress". |
242 |
greg |
2.1 |
* |
243 |
|
|
*/ |
244 |
|
|
|
245 |
|
|
/***************************************************************************** |
246 |
|
|
* |
247 |
|
|
* GIFENCODE.C - GIF Image compression interface |
248 |
|
|
* |
249 |
|
|
* GIFEncode( FName, GHeight, GWidth, GInterlace, Background, |
250 |
|
|
* BitsPerPixel, Red, Green, Blue, GetPixel ) |
251 |
|
|
* |
252 |
|
|
*****************************************************************************/ |
253 |
|
|
|
254 |
|
|
#define TRUE 1 |
255 |
|
|
#define FALSE 0 |
256 |
|
|
|
257 |
|
|
int Width, Height; |
258 |
|
|
int curx, cury; |
259 |
|
|
long CountDown; |
260 |
|
|
int Pass; |
261 |
|
|
int Interlace; |
262 |
|
|
unsigned long cur_accum = 0; |
263 |
|
|
int cur_bits = 0; |
264 |
|
|
|
265 |
schorsch |
2.11 |
static void BumpPixel(void); |
266 |
|
|
static int GIFNextPixel(ifun_t* getpixel); |
267 |
|
|
static void Putword(int w, FILE *fp); |
268 |
|
|
static void compress(int init_bits, FILE *outfile, ifun_t* ReadValue); |
269 |
|
|
|
270 |
|
|
|
271 |
|
|
/* a code_int must be able to hold 2**CBITS values of type int, and also -1 */ |
272 |
|
|
typedef int code_int; |
273 |
|
|
typedef long int count_int; |
274 |
|
|
typedef unsigned char char_type; |
275 |
|
|
|
276 |
|
|
static void output(code_int code); |
277 |
|
|
static void cl_block(void); |
278 |
|
|
static void cl_hash(count_int hsize); |
279 |
|
|
static void writeerr(void); |
280 |
|
|
|
281 |
|
|
static void char_init(void); |
282 |
|
|
static void char_out(int c); |
283 |
|
|
static void flush_char(void); |
284 |
|
|
static void gammawarp(short *sbuf, float gam, int n); |
285 |
|
|
|
286 |
|
|
|
287 |
greg |
2.1 |
/* |
288 |
|
|
* Bump the 'curx' and 'cury' to point to the next pixel |
289 |
|
|
*/ |
290 |
schorsch |
2.11 |
static void |
291 |
|
|
BumpPixel(void) |
292 |
greg |
2.1 |
{ |
293 |
|
|
curx++; |
294 |
|
|
if( curx == Width ) { |
295 |
|
|
curx = 0; |
296 |
|
|
if( !Interlace ) { |
297 |
|
|
cury++; |
298 |
|
|
} else { |
299 |
|
|
switch( Pass ) { |
300 |
|
|
case 0: |
301 |
|
|
cury += 8; |
302 |
|
|
if( cury >= Height ) { |
303 |
|
|
Pass++; |
304 |
|
|
cury = 4; |
305 |
|
|
} |
306 |
|
|
break; |
307 |
|
|
case 1: |
308 |
|
|
cury += 8; |
309 |
|
|
if( cury >= Height ) { |
310 |
|
|
Pass++; |
311 |
|
|
cury = 2; |
312 |
|
|
} |
313 |
|
|
break; |
314 |
|
|
case 2: |
315 |
|
|
cury += 4; |
316 |
|
|
if( cury >= Height ) { |
317 |
|
|
Pass++; |
318 |
|
|
cury = 1; |
319 |
|
|
} |
320 |
|
|
break; |
321 |
|
|
case 3: |
322 |
|
|
cury += 2; |
323 |
|
|
break; |
324 |
|
|
} |
325 |
|
|
} |
326 |
|
|
} |
327 |
|
|
} |
328 |
|
|
|
329 |
|
|
/* |
330 |
|
|
* Return the next pixel from the image |
331 |
|
|
*/ |
332 |
schorsch |
2.11 |
static int |
333 |
|
|
GIFNextPixel( |
334 |
|
|
ifun_t* getpixel |
335 |
|
|
) |
336 |
greg |
2.1 |
{ |
337 |
|
|
int r; |
338 |
|
|
|
339 |
|
|
if( CountDown == 0 ) |
340 |
|
|
return EOF; |
341 |
|
|
CountDown--; |
342 |
|
|
r = (*getpixel)( curx, cury ); |
343 |
|
|
BumpPixel(); |
344 |
|
|
return r; |
345 |
|
|
} |
346 |
|
|
|
347 |
|
|
/* |
348 |
|
|
* public GIFEncode |
349 |
|
|
*/ |
350 |
schorsch |
2.11 |
static void |
351 |
|
|
GIFEncode( |
352 |
|
|
FILE *fp, |
353 |
|
|
int GWidth, |
354 |
|
|
int GHeight, |
355 |
|
|
int GInterlace, |
356 |
|
|
int Background, |
357 |
|
|
int BitsPerPixel, |
358 |
|
|
int Red[], |
359 |
|
|
int Green[], |
360 |
|
|
int Blue[], |
361 |
|
|
ifun_t* GetPixel |
362 |
|
|
) |
363 |
greg |
2.1 |
{ |
364 |
|
|
int B; |
365 |
|
|
int RWidth, RHeight; |
366 |
|
|
int LeftOfs, TopOfs; |
367 |
|
|
int Resolution; |
368 |
|
|
int ColorMapSize; |
369 |
|
|
int InitCodeSize; |
370 |
|
|
int i; |
371 |
|
|
|
372 |
schorsch |
2.11 |
cur_accum = 0; /* globals */ |
373 |
greg |
2.1 |
cur_bits = 0; |
374 |
|
|
|
375 |
|
|
Interlace = GInterlace; |
376 |
|
|
ColorMapSize = 1 << BitsPerPixel; |
377 |
|
|
RWidth = Width = GWidth; |
378 |
|
|
RHeight = Height = GHeight; |
379 |
|
|
LeftOfs = TopOfs = 0; |
380 |
|
|
Resolution = BitsPerPixel; |
381 |
|
|
|
382 |
|
|
CountDown = (long)Width * (long)Height; |
383 |
|
|
Pass = 0; |
384 |
|
|
if( BitsPerPixel <= 1 ) |
385 |
|
|
InitCodeSize = 2; |
386 |
|
|
else |
387 |
|
|
InitCodeSize = BitsPerPixel; |
388 |
|
|
curx = cury = 0; |
389 |
|
|
fwrite( "GIF87a", 1, 6, fp ); |
390 |
|
|
Putword( RWidth, fp ); |
391 |
|
|
Putword( RHeight, fp ); |
392 |
|
|
B = 0x80; /* Yes, there is a color map */ |
393 |
|
|
B |= (Resolution - 1) << 5; |
394 |
|
|
B |= (BitsPerPixel - 1); |
395 |
|
|
fputc( B, fp ); |
396 |
|
|
fputc( Background, fp ); |
397 |
|
|
fputc( 0, fp ); |
398 |
|
|
for( i=0; i<ColorMapSize; i++ ) { |
399 |
|
|
fputc( Red[i], fp ); |
400 |
|
|
fputc( Green[i], fp ); |
401 |
|
|
fputc( Blue[i], fp ); |
402 |
|
|
} |
403 |
|
|
fputc( ',', fp ); |
404 |
|
|
Putword( LeftOfs, fp ); |
405 |
|
|
Putword( TopOfs, fp ); |
406 |
|
|
Putword( Width, fp ); |
407 |
|
|
Putword( Height, fp ); |
408 |
|
|
if( Interlace ) |
409 |
|
|
fputc( 0x40, fp ); |
410 |
|
|
else |
411 |
|
|
fputc( 0x00, fp ); |
412 |
|
|
fputc( InitCodeSize, fp ); |
413 |
|
|
compress( InitCodeSize+1, fp, GetPixel ); |
414 |
|
|
fputc( 0, fp ); |
415 |
|
|
fputc( ';', fp ); |
416 |
|
|
fclose( fp ); |
417 |
|
|
} |
418 |
|
|
|
419 |
|
|
/* |
420 |
|
|
* Write out a word to the GIF file |
421 |
|
|
*/ |
422 |
schorsch |
2.11 |
static void |
423 |
|
|
Putword( |
424 |
|
|
int w, |
425 |
|
|
FILE *fp |
426 |
|
|
) |
427 |
greg |
2.1 |
{ |
428 |
|
|
fputc( w & 0xff, fp ); |
429 |
|
|
fputc( (w/256) & 0xff, fp ); |
430 |
|
|
} |
431 |
|
|
|
432 |
|
|
|
433 |
|
|
/*************************************************************************** |
434 |
|
|
* |
435 |
|
|
* GIFCOMPR.C - GIF Image compression routines |
436 |
|
|
* |
437 |
|
|
* Lempel-Ziv compression based on 'compress'. GIF modifications by |
438 |
|
|
* David Rowley ([email protected]) |
439 |
|
|
* |
440 |
|
|
***************************************************************************/ |
441 |
|
|
|
442 |
|
|
#define CBITS 12 |
443 |
|
|
#define HSIZE 5003 /* 80% occupancy */ |
444 |
|
|
|
445 |
|
|
/* |
446 |
|
|
* |
447 |
|
|
* GIF Image compression - modified 'compress' |
448 |
|
|
* |
449 |
|
|
* Based on: compress.c - File compression ala IEEE Computer, June 1984. |
450 |
|
|
* |
451 |
|
|
* By Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas) |
452 |
|
|
* Jim McKie (decvax!mcvax!jim) |
453 |
|
|
* Steve Davies (decvax!vax135!petsd!peora!srd) |
454 |
|
|
* Ken Turkowski (decvax!decwrl!turtlevax!ken) |
455 |
|
|
* James A. Woods (decvax!ihnp4!ames!jaw) |
456 |
|
|
* Joe Orost (decvax!vax135!petsd!joe) |
457 |
|
|
* |
458 |
|
|
*/ |
459 |
|
|
#include <ctype.h> |
460 |
|
|
|
461 |
|
|
#define ARGVAL() (*++(*argv) || (--argc && *++argv)) |
462 |
|
|
|
463 |
|
|
int n_bits; /* number of bits/code */ |
464 |
|
|
int maxbits = CBITS; /* user settable max # bits/code */ |
465 |
|
|
code_int maxcode; /* maximum code, given n_bits */ |
466 |
|
|
code_int maxmaxcode = (code_int)1 << CBITS; /* should NEVER generate this code */ |
467 |
|
|
# define MAXCODE(n_bits) (((code_int) 1 << (n_bits)) - 1) |
468 |
|
|
|
469 |
|
|
count_int htab [HSIZE]; |
470 |
|
|
unsigned short codetab [HSIZE]; |
471 |
|
|
#define HashTabOf(i) htab[i] |
472 |
|
|
#define CodeTabOf(i) codetab[i] |
473 |
|
|
|
474 |
|
|
code_int hsize = HSIZE; /* for dynamic table sizing */ |
475 |
|
|
|
476 |
|
|
/* |
477 |
|
|
* To save much memory, we overlay the table used by compress() with those |
478 |
|
|
* used by decompress(). The tab_prefix table is the same size and type |
479 |
|
|
* as the codetab. The tab_suffix table needs 2**CBITS characters. We |
480 |
|
|
* get this from the beginning of htab. The output stack uses the rest |
481 |
|
|
* of htab, and contains characters. There is plenty of room for any |
482 |
|
|
* possible stack (stack used to be 8000 characters). |
483 |
|
|
*/ |
484 |
|
|
#define tab_prefixof(i) CodeTabOf(i) |
485 |
|
|
#define tab_suffixof(i) ((char_type *)(htab))[i] |
486 |
|
|
#define de_stack ((char_type *)&tab_suffixof((code_int)1<<CBITS)) |
487 |
|
|
|
488 |
|
|
code_int free_ent = 0; /* first unused entry */ |
489 |
|
|
|
490 |
|
|
/* |
491 |
|
|
* block compression parameters -- after all codes are used up, |
492 |
|
|
* and compression rate changes, start over. |
493 |
|
|
*/ |
494 |
|
|
int clear_flg = 0; |
495 |
|
|
int offset; |
496 |
|
|
long int in_count = 1; /* length of input */ |
497 |
|
|
long int out_count = 0; /* # of codes output (for debugging) */ |
498 |
|
|
|
499 |
|
|
/* |
500 |
|
|
* compress stdin to stdout |
501 |
|
|
* |
502 |
|
|
* Algorithm: use open addressing double hashing (no chaining) on the |
503 |
|
|
* prefix code / next character combination. We do a variant of Knuth's |
504 |
|
|
* algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime |
505 |
|
|
* secondary probe. Here, the modular division first probe is gives way |
506 |
|
|
* to a faster exclusive-or manipulation. Also do block compression with |
507 |
|
|
* an adaptive reset, whereby the code table is cleared when the compression |
508 |
|
|
* ratio decreases, but after the table fills. The variable-length output |
509 |
|
|
* codes are re-sized at this point, and a special CLEAR code is generated |
510 |
|
|
* for the decompressor. Late addition: construct the table according to |
511 |
|
|
* file size for noticeable speed improvement on small files. Please direct |
512 |
|
|
* questions about this implementation to ames!jaw. |
513 |
|
|
*/ |
514 |
|
|
|
515 |
|
|
int g_init_bits; |
516 |
|
|
FILE *g_outfile; |
517 |
|
|
int ClearCode; |
518 |
|
|
int EOFCode; |
519 |
|
|
|
520 |
schorsch |
2.11 |
static void |
521 |
|
|
compress( |
522 |
|
|
int init_bits, |
523 |
|
|
FILE *outfile, |
524 |
|
|
ifun_t* ReadValue |
525 |
|
|
) |
526 |
greg |
2.1 |
{ |
527 |
|
|
register long fcode; |
528 |
|
|
register code_int i = 0; |
529 |
|
|
register int c; |
530 |
|
|
register code_int ent; |
531 |
|
|
register code_int disp; |
532 |
|
|
register code_int hsize_reg; |
533 |
|
|
register int hshift; |
534 |
|
|
|
535 |
|
|
/* |
536 |
|
|
* Set up the globals: g_init_bits - initial number of bits |
537 |
|
|
* g_outfile - pointer to output file |
538 |
|
|
*/ |
539 |
|
|
g_init_bits = init_bits; |
540 |
|
|
g_outfile = outfile; |
541 |
|
|
/* |
542 |
|
|
* Set up the necessary values |
543 |
|
|
*/ |
544 |
|
|
offset = 0; |
545 |
|
|
out_count = 0; |
546 |
|
|
clear_flg = 0; |
547 |
|
|
in_count = 1; |
548 |
|
|
maxcode = MAXCODE(n_bits = g_init_bits); |
549 |
|
|
ClearCode = (1 << (init_bits - 1)); |
550 |
|
|
EOFCode = ClearCode + 1; |
551 |
|
|
free_ent = ClearCode + 2; |
552 |
|
|
char_init(); |
553 |
|
|
ent = GIFNextPixel( ReadValue ); |
554 |
|
|
hshift = 0; |
555 |
|
|
for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L ) |
556 |
|
|
hshift++; |
557 |
|
|
hshift = 8 - hshift; /* set hash code range bound */ |
558 |
|
|
hsize_reg = hsize; |
559 |
|
|
cl_hash( (count_int) hsize_reg); /* clear hash table */ |
560 |
|
|
output( (code_int)ClearCode ); |
561 |
|
|
while ( (c = GIFNextPixel( ReadValue )) != EOF ) { |
562 |
|
|
in_count++; |
563 |
|
|
fcode = (long) (((long) c << maxbits) + ent); |
564 |
schorsch |
2.11 |
/* i = (((code_int)c << hshift) ~ ent); */ /* xor hashing */ |
565 |
greg |
2.1 |
i = (((code_int)c << hshift) ^ ent); /* xor hashing */ |
566 |
|
|
if ( HashTabOf (i) == fcode ) { |
567 |
|
|
ent = CodeTabOf (i); |
568 |
|
|
continue; |
569 |
|
|
} else if ( (long)HashTabOf (i) < 0 ) /* empty slot */ |
570 |
|
|
goto nomatch; |
571 |
|
|
disp = hsize_reg - i; /* secondary hash (after G. Knott) */ |
572 |
|
|
if ( i == 0 ) |
573 |
|
|
disp = 1; |
574 |
|
|
probe: |
575 |
|
|
if ( (i -= disp) < 0 ) |
576 |
|
|
i += hsize_reg; |
577 |
|
|
if ( HashTabOf (i) == fcode ) { |
578 |
|
|
ent = CodeTabOf (i); |
579 |
|
|
continue; |
580 |
|
|
} |
581 |
|
|
if ( (long)HashTabOf (i) > 0 ) |
582 |
|
|
goto probe; |
583 |
|
|
nomatch: |
584 |
|
|
output ( (code_int) ent ); |
585 |
|
|
out_count++; |
586 |
|
|
ent = c; |
587 |
|
|
if ( free_ent < maxmaxcode ) { |
588 |
|
|
CodeTabOf (i) = free_ent++; /* code -> hashtable */ |
589 |
|
|
HashTabOf (i) = fcode; |
590 |
|
|
} else |
591 |
|
|
cl_block(); |
592 |
|
|
} |
593 |
|
|
/* |
594 |
|
|
* Put out the final code. |
595 |
|
|
*/ |
596 |
|
|
output( (code_int)ent ); |
597 |
|
|
out_count++; |
598 |
|
|
output( (code_int) EOFCode ); |
599 |
|
|
return; |
600 |
|
|
} |
601 |
|
|
|
602 |
|
|
/***************************************************************** |
603 |
|
|
* TAG( output ) |
604 |
|
|
* |
605 |
|
|
* Output the given code. |
606 |
|
|
* Inputs: |
607 |
|
|
* code: A n_bits-bit integer. If == -1, then EOF. This assumes |
608 |
|
|
* that n_bits =< (long)wordsize - 1. |
609 |
|
|
* Outputs: |
610 |
|
|
* Outputs code to the file. |
611 |
|
|
* Assumptions: |
612 |
|
|
* Chars are 8 bits long. |
613 |
|
|
* Algorithm: |
614 |
|
|
* Maintain a CBITS character long buffer (so that 8 codes will |
615 |
|
|
* fit in it exactly). Use the VAX insv instruction to insert each |
616 |
|
|
* code in turn. When the buffer fills up empty it and start over. |
617 |
|
|
*/ |
618 |
|
|
|
619 |
|
|
unsigned long masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F, |
620 |
|
|
0x001F, 0x003F, 0x007F, 0x00FF, |
621 |
|
|
0x01FF, 0x03FF, 0x07FF, 0x0FFF, |
622 |
|
|
0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF }; |
623 |
|
|
|
624 |
schorsch |
2.11 |
static void |
625 |
|
|
output( |
626 |
|
|
code_int code |
627 |
|
|
) |
628 |
greg |
2.1 |
{ |
629 |
|
|
cur_accum &= masks[ cur_bits ]; |
630 |
|
|
if( cur_bits > 0 ) |
631 |
|
|
cur_accum |= ((long)code << cur_bits); |
632 |
|
|
else |
633 |
|
|
cur_accum = code; |
634 |
|
|
cur_bits += n_bits; |
635 |
|
|
while( cur_bits >= 8 ) { |
636 |
|
|
char_out( (unsigned int)(cur_accum & 0xff) ); |
637 |
|
|
cur_accum >>= 8; |
638 |
|
|
cur_bits -= 8; |
639 |
|
|
} |
640 |
|
|
|
641 |
|
|
/* |
642 |
|
|
* If the next entry is going to be too big for the code size, |
643 |
|
|
* then increase it, if possible. |
644 |
|
|
*/ |
645 |
|
|
if ( free_ent > maxcode || clear_flg ) { |
646 |
|
|
if( clear_flg ) { |
647 |
|
|
maxcode = MAXCODE (n_bits = g_init_bits); |
648 |
|
|
clear_flg = 0; |
649 |
|
|
} else { |
650 |
|
|
n_bits++; |
651 |
|
|
if ( n_bits == maxbits ) |
652 |
|
|
maxcode = maxmaxcode; |
653 |
|
|
else |
654 |
|
|
maxcode = MAXCODE(n_bits); |
655 |
|
|
} |
656 |
|
|
} |
657 |
|
|
if( code == EOFCode ) { |
658 |
|
|
/* |
659 |
|
|
* At EOF, write the rest of the buffer. |
660 |
|
|
*/ |
661 |
|
|
while( cur_bits > 0 ) { |
662 |
|
|
char_out( (unsigned int)(cur_accum & 0xff) ); |
663 |
|
|
cur_accum >>= 8; |
664 |
|
|
cur_bits -= 8; |
665 |
|
|
} |
666 |
|
|
flush_char(); |
667 |
|
|
fflush( g_outfile ); |
668 |
|
|
if( ferror( g_outfile ) ) |
669 |
|
|
writeerr(); |
670 |
|
|
} |
671 |
|
|
} |
672 |
|
|
|
673 |
|
|
/* |
674 |
|
|
* Clear out the hash table |
675 |
|
|
*/ |
676 |
schorsch |
2.11 |
static void |
677 |
|
|
cl_block (void) /* table clear for block compress */ |
678 |
greg |
2.1 |
{ |
679 |
|
|
cl_hash ( (count_int) hsize ); |
680 |
|
|
free_ent = ClearCode + 2; |
681 |
|
|
clear_flg = 1; |
682 |
|
|
output( (code_int)ClearCode ); |
683 |
|
|
} |
684 |
|
|
|
685 |
schorsch |
2.11 |
static void |
686 |
|
|
cl_hash( /* reset code table */ |
687 |
|
|
register count_int hsize |
688 |
|
|
) |
689 |
greg |
2.1 |
{ |
690 |
|
|
register count_int *htab_p = htab+hsize; |
691 |
|
|
register long i; |
692 |
|
|
register long m1 = -1; |
693 |
|
|
|
694 |
|
|
i = hsize - 16; |
695 |
|
|
do { /* might use Sys V memset(3) here */ |
696 |
|
|
*(htab_p-16) = m1; |
697 |
|
|
*(htab_p-15) = m1; |
698 |
|
|
*(htab_p-14) = m1; |
699 |
|
|
*(htab_p-13) = m1; |
700 |
|
|
*(htab_p-12) = m1; |
701 |
|
|
*(htab_p-11) = m1; |
702 |
|
|
*(htab_p-10) = m1; |
703 |
|
|
*(htab_p-9) = m1; |
704 |
|
|
*(htab_p-8) = m1; |
705 |
|
|
*(htab_p-7) = m1; |
706 |
|
|
*(htab_p-6) = m1; |
707 |
|
|
*(htab_p-5) = m1; |
708 |
|
|
*(htab_p-4) = m1; |
709 |
|
|
*(htab_p-3) = m1; |
710 |
|
|
*(htab_p-2) = m1; |
711 |
|
|
*(htab_p-1) = m1; |
712 |
|
|
htab_p -= 16; |
713 |
|
|
} while ((i -= 16) >= 0); |
714 |
|
|
for ( i += 16; i > 0; i-- ) |
715 |
|
|
*--htab_p = m1; |
716 |
|
|
} |
717 |
|
|
|
718 |
schorsch |
2.11 |
static void |
719 |
|
|
writeerr(void) |
720 |
greg |
2.1 |
{ |
721 |
|
|
printf( "error writing output file\n" ); |
722 |
|
|
exit(1); |
723 |
|
|
} |
724 |
|
|
|
725 |
|
|
/****************************************************************************** |
726 |
|
|
* |
727 |
|
|
* GIF Specific routines |
728 |
|
|
* |
729 |
|
|
******************************************************************************/ |
730 |
|
|
|
731 |
|
|
/* |
732 |
|
|
* Number of characters so far in this 'packet' |
733 |
|
|
*/ |
734 |
|
|
int a_count; |
735 |
|
|
|
736 |
|
|
/* |
737 |
|
|
* Set up the 'byte output' routine |
738 |
|
|
*/ |
739 |
schorsch |
2.11 |
static void |
740 |
|
|
char_init(void) |
741 |
greg |
2.1 |
{ |
742 |
|
|
a_count = 0; |
743 |
|
|
} |
744 |
|
|
|
745 |
|
|
/* |
746 |
|
|
* Define the storage for the packet accumulator |
747 |
|
|
*/ |
748 |
|
|
char accum[256]; |
749 |
|
|
|
750 |
|
|
/* |
751 |
|
|
* Add a character to the end of the current packet, and if it is 254 |
752 |
|
|
* characters, flush the packet to disk. |
753 |
|
|
*/ |
754 |
schorsch |
2.11 |
static void |
755 |
|
|
char_out( |
756 |
|
|
int c |
757 |
|
|
) |
758 |
greg |
2.1 |
{ |
759 |
|
|
accum[ a_count++ ] = c; |
760 |
|
|
if( a_count >= 254 ) |
761 |
|
|
flush_char(); |
762 |
|
|
} |
763 |
|
|
|
764 |
|
|
/* |
765 |
|
|
* Flush the packet to disk, and reset the accumulator |
766 |
|
|
*/ |
767 |
schorsch |
2.11 |
static void |
768 |
|
|
flush_char(void) |
769 |
greg |
2.1 |
{ |
770 |
|
|
if( a_count > 0 ) { |
771 |
|
|
fputc( a_count, g_outfile ); |
772 |
|
|
fwrite( accum, 1, a_count, g_outfile ); |
773 |
|
|
a_count = 0; |
774 |
|
|
} |
775 |
|
|
} |
776 |
|
|
|
777 |
|
|
static float curgamma; |
778 |
|
|
static short gamtab[256]; |
779 |
|
|
|
780 |
schorsch |
2.11 |
static void |
781 |
|
|
gammawarp( |
782 |
|
|
short *sbuf, |
783 |
|
|
float gam, |
784 |
|
|
int n |
785 |
|
|
) |
786 |
greg |
2.1 |
{ |
787 |
|
|
int i; |
788 |
|
|
|
789 |
|
|
if(gam!=curgamma) { |
790 |
|
|
for(i=0; i<256; i++) |
791 |
|
|
gamtab[i] = 255*pow(i/255.0,gam)+0.5; |
792 |
|
|
curgamma = gam; |
793 |
|
|
} |
794 |
|
|
while(n--) { |
795 |
|
|
*sbuf = gamtab[*sbuf]; |
796 |
|
|
sbuf++; |
797 |
|
|
} |
798 |
|
|
} |