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/ Developer CD Series 1992 June: ROMin Holiday / ADC Developer CD (1992-06) (''ROMin Holiday'')_iso / Developer Connection - 06-1992.iso / Periodicals / develop / develop Issue 6 / develop Issue 6.rsrc / PICT_206_page 43.png < prev    next >
Portable Network Graphic  |  1992-04-09  |  63.9 KB  |  547x727  |  16-bit (607 colors)
   ocr: Asvou know. when pixel data is included in a PICT. the THE LOW-DOWN ON IMAGE COMPRESSION BY FORREST TANAKA encoding of bytes (that is, the PackBits routine), buthere the asterisks mark the flag counter byte compressing direct pixels using run-length encodingthat you can't assume the pixel values are wor doesnt work very well. Here's what QuickDraw doesackBits packs data 127 bytes at a time, for u with direct pixels in PICTS: 32,767 total bytes; similarly, the internal cor routine packs data 127 words at a time. If the packType field contains 1, no compression is done at al. The complete pixel ...