Re: cOMp chunk [was: EXIF support in PNG]
Glenn Randers-Pehrson <[email protected]>
| Newsgroups | gmane.comp.graphics.png.general |
|---|---|
| Message-ID | <CA+PdXcvqsrNZH2Vx=8uncE2HSdq-wg3DjmEyxHRm2jRsmDA-sw@mail.gmail.com> |
Willem, would you allow a compression byte on the eXIf chunk, then? Glenn On Sun, Jan 1, 2017 at 2:35 PM, Glenn Randers-Pehrson <[email protected]> wrote: > Not COMp -- according to the PNG spec, "the safe-to-copy bit will always > be 0 for critical chunks". > > Glenn > > On Sun, Jan 1, 2017 at 2:07 PM, John Bowler <john.cunningham.bowler@gmail. > com> wrote: > >> On Sun, Jan 1, 2017 at 11:00 AM, Soni L. <[email protected]> wrote: >> >>> >>> Why not make it COMP and require everything to verify the inner chunk? >>> That way COMP could be added to chunks like PLTE and stuff. >>> >> >> I'm suggesting a set of four chunks; cOMp, cOMP, COMp and COMP, but I've >> just realized that PLTE cannot be compressed without violating the >> specification because that would result in a file that cannot be read by a >> fully conformant ISO-PNG decoder, so it wouldn't be a PNG. >> >> PLTE on color type != 3 (not palette) cannot even be compressed using >> cOMP because the potential result is a PNG that contains multiple PLTE >> chunks. >> >> Hum, this requires a little thought; I'm not sure unknown chunks can be >> compressed this way. >> >> John Bowler >> >> ------------------------------------------------------------ >> ------------------ >> Check out the vibrant tech community on one of the world's most >> engaging tech sites, SlashDot.org! http://sdm.link/slashdot >> _______________________________________________ >> png-mng-misc mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/png-mng-misc >> >> > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ png-mng-misc mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/png-mng-misc