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1993.08.17 13:32 "Re: byte swapping 16- and 32-bit data", by Gaile G. Gordon
- 1993.08.17 13:54 "Re: byte swapping 16- and 32-bit data", by Quincey Koziol
- 1993.08.17 14:55 "Re: byte swapping 16- and 32-bit data", by Sam Leffler
- 1993.08.17 20:45 "Re: byte swapping 16- and 32-bit data", by Richard Minner
1993.08.17 20:45 "Re: byte swapping 16- and 32-bit data", by Richard Minner
(Oh boy, design by committee, what fun! I'll bet Sam is thrilled. ;-)
Here's my proposal:
Libtiff provides swabbing for >8-bit samples, but not un-avoidably. Libtiff already provides a number of ways of reading pixel data; I suggest providing the following behaviors, with two new trivial routines:
Do swab:
TIFFReadRGBAImage() should always swab, even now
TIFFReadScanline() "fix" to always swab
TIFFReadEncodedStrip() ditto
TIFFReadEncodedTile() ditto
TIFFReadTile() ditto
Don't swab:
TIFFReadRawStrip() as always, "raw bytes"
TIFFReadRawTile() ditto
new TIFFReadEncodedStripNoSwab() decode without swab
new TIFFReadEncodedTileNoSwab() ditto
? new TIFFReadTileNoSwab() (not really needed)
This just involves renaming TIFFReadEncoded*() to
TIFFReadEncoded*NoSwab() and providing TIFFReadEncoded*()
as simple wrappers that do the swabbing no done only in tif_dumpmode.c:DumpModeDecode(). I probably wouldn't bother providing TIFFReadTileNoSwab() since swab-avoiding clients can just use TIFFReadEncodedTileNoSwab() with little added overhead.
[Note: any direct replies use rtm@island.com explicitly; my return address is likely to be bogus.]
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Richard Minner rtm@island.com {uunet,sun,well}!island!rtm
Island Graphics Corporation Sacramento, CA (916) 736-1323