Re: BGRA, ARGB, etc. suggestion
Glenn Randers-Pehrson <[email protected]>
| Newsgroups | gmane.comp.graphics.png.general |
|---|---|
| Message-ID | <CA+PdXcsO-Md1J7DegDYX+QQTQwG3kG2YQ3Ed=qAf5RTQjgVAiQ@mail.gmail.com> |
chNL would compete with Apple's CgBI chunk and perhaps violate their "patent applied for". Even though the proposed name is different, it would serve the same purpose: making PNG files unreadable. Libpng supports BGRA and ARGB (reads RGBA pixels from a PNG file and converts them on-the-fly to your desired format. Supporting 32-bit samples would not be trivial because the spec and library would have to be redone to allow values greater than (2^31 - 1) so I don't expect that proposal would be accepted. The PNG specification itself says that chunks like chNL and CgBI violate the guidelines for new PNG chunk types: http://www.w3.org/TR/PNG/#B-NewChunksAppendix "Do not define new chunks that redefine the meaning of existing chunks or change the interpretation of an existing standardized chunk, e.g., do not add a new chunk to say that RGB and alpha values actually mean CMYK." Glenn On Sun, Dec 20, 2015 at 3:16 PM, Alexey Solovey <[email protected]> wrote: > Hello. I suggest to make chNL chunk for declare how should works png: in > BGRA, ARGB, or another format. Also I suggest 32-bit grayscale support. > Probably, I suggest maSK, that released in BMP format. Glenn? > > > ------------------------------------------------------------------------------ > > _______________________________________________ > png-mng-misc mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/png-mng-misc > > ------------------------------------------------------------------------------ _______________________________________________ png-mng-misc mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/png-mng-misc