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Diffstat (limited to 'compress.c')
| -rw-r--r-- | compress.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/compress.c b/compress.c new file mode 100644 index 0000000..3c97806 --- /dev/null +++ b/compress.c @@ -0,0 +1,205 @@ +/* + * Compface - 48x48x1 image compression and decompression + * + * Copyright (c) James Ashton - Sydney University - June 1990. + * + * Written 11th November 1989. + * + * Permission is given to distribute these sources, as long as the + * copyright messages are not removed, and no monies are exchanged. + * + * No responsibility is taken for any errors on inaccuracies inherent + * either to the comments or the code of this program, but if reported + * to me, then an attempt will be made to fix them. + */ + + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "compface.h" + +int +Same(f, wid, hei) +register char *f; +register int wid, hei; +{ + register char val, *row; + register int x; + + val = *f; + while (hei--) + { + row = f; + x = wid; + while (x--) + if (*(row++) != val) + return(0); + f += WIDTH; + } + return 1; +} + +int +AllBlack(f, wid, hei) +char *f; +int wid, hei; +{ + if (wid > 3) + { + wid /= 2; + hei /= 2; + return (AllBlack(f, wid, hei) && AllBlack(f + wid, wid, hei) && + AllBlack(f + WIDTH * hei, wid, hei) && + AllBlack(f + WIDTH * hei + wid, wid, hei)); + } + else + return (*f || *(f + 1) || *(f + WIDTH) || *(f + WIDTH + 1)); +} + +int +AllWhite(f, wid, hei) +char *f; +int wid, hei; +{ + return ((*f == 0) && Same(f, wid, hei)); +} + +void +PopGreys(f, wid, hei) +char *f; +int wid, hei; +{ + if (wid > 3) + { + wid /= 2; + hei /= 2; + PopGreys(f, wid, hei); + PopGreys(f + wid, wid, hei); + PopGreys(f + WIDTH * hei, wid, hei); + PopGreys(f + WIDTH * hei + wid, wid, hei); + } + else + { + wid = BigPop(freqs); + if (wid & 1) + *f = 1; + if (wid & 2) + *(f + 1) = 1; + if (wid & 4) + *(f + WIDTH) = 1; + if (wid & 8) + *(f + WIDTH + 1) = 1; + } +} + +void +PushGreys(f, wid, hei) +char *f; +int wid, hei; +{ + if (wid > 3) + { + wid /= 2; + hei /= 2; + PushGreys(f, wid, hei); + PushGreys(f + wid, wid, hei); + PushGreys(f + WIDTH * hei, wid, hei); + PushGreys(f + WIDTH * hei + wid, wid, hei); + } + else + RevPush(freqs + *f + 2 * *(f + 1) + 4 * *(f + WIDTH) + + 8 * *(f + WIDTH + 1)); +} + +void +UnCompress(f, wid, hei, lev) +register char *f; +register int wid, hei, lev; +{ + switch (BigPop(&levels[lev][0])) + { + case WHITE : + return; + case BLACK : + PopGreys(f, wid, hei); + return; + default : + wid /= 2; + hei /= 2; + lev++; + UnCompress(f, wid, hei, lev); + UnCompress(f + wid, wid, hei, lev); + UnCompress(f + hei * WIDTH, wid, hei, lev); + UnCompress(f + wid + hei * WIDTH, wid, hei, lev); + return; + } +} + +void +Compress(f, wid, hei, lev) +register char *f; +register int wid, hei, lev; +{ + if (AllWhite(f, wid, hei)) + { + RevPush(&levels[lev][WHITE]); + return; + } + if (AllBlack(f, wid, hei)) + { + RevPush(&levels[lev][BLACK]); + PushGreys(f, wid, hei); + return; + } + RevPush(&levels[lev][GREY]); + wid /= 2; + hei /= 2; + lev++; + Compress(f, wid, hei, lev); + Compress(f + wid, wid, hei, lev); + Compress(f + hei * WIDTH, wid, hei, lev); + Compress(f + wid + hei * WIDTH, wid, hei, lev); +} + +void +UnCompAll(fbuf) +char *fbuf; +{ + register char *p; + + BigClear(); + BigRead(fbuf); + p = F; + while (p < F + PIXELS) + *(p++) = 0; + UnCompress(F, 16, 16, 0); + UnCompress(F + 16, 16, 16, 0); + UnCompress(F + 32, 16, 16, 0); + UnCompress(F + WIDTH * 16, 16, 16, 0); + UnCompress(F + WIDTH * 16 + 16, 16, 16, 0); + UnCompress(F + WIDTH * 16 + 32, 16, 16, 0); + UnCompress(F + WIDTH * 32, 16, 16, 0); + UnCompress(F + WIDTH * 32 + 16, 16, 16, 0); + UnCompress(F + WIDTH * 32 + 32, 16, 16, 0); +} + +void +CompAll(fbuf) +char *fbuf; +{ + Compress(F, 16, 16, 0); + Compress(F + 16, 16, 16, 0); + Compress(F + 32, 16, 16, 0); + Compress(F + WIDTH * 16, 16, 16, 0); + Compress(F + WIDTH * 16 + 16, 16, 16, 0); + Compress(F + WIDTH * 16 + 32, 16, 16, 0); + Compress(F + WIDTH * 32, 16, 16, 0); + Compress(F + WIDTH * 32 + 16, 16, 16, 0); + Compress(F + WIDTH * 32 + 32, 16, 16, 0); + BigClear(); + while (NumProbs > 0) + BigPush(ProbBuf[--NumProbs]); + BigWrite(fbuf); +} |