Re: Endless gamma in eXIf 2017-0119
Glenn Randers-Pehrson <[email protected]>
| Newsgroups | gmane.comp.graphics.png.general |
|---|---|
| Message-ID | <CA+PdXcspO-2pO+_v-kQy=pkhF8ULWQCJG6vbnPU72o7qBraxVw@mail.gmail.com> |
On Mon, Feb 6, 2017 at 8:34 AM, Pavel Zlatovratskii <[email protected]> wrote: > I think yes, but this will cause remove of still valid camera > metadata(like lens model, etc). > > Such dilemma caused by eXIf's 'image header within image header' nature... > > That's why using EXIF is good only as fast solution, more PNG-native way > to save data from EXIF still required. > Besides the hex-encoded-Exif-in-zTXt, ImageMagick writes much of the Exif information in separate tEXt or zTXt chunks, each containing the information from one Exif tag. But I don't think there is any attempt to read those back in to a new image; they are just informative. It's a bit of a mess, with redundant storage of various pieces of information, that can become invalid. I haven't actually seen the problem with gamma, but I have seen problems with Exif "density" conflicting with PNG "pHYs" and with the ImageMagick convert "-resolution" option. Glenn ------------------------------------------------------------------------------ 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