Re: CALL for DISCUSSION: eXIf 20170115
Glenn Randers-Pehrson <[email protected]>
| Newsgroups | gmane.comp.graphics.png.general |
|---|---|
| Message-ID | <CA+PdXct6asF-8ySpZoJREfEK8w8kvdxRO1Wb+nqH0OpUmVOGUg@mail.gmail.com> |
On Mon, Jan 30, 2017 at 10:42 PM, John Bowler < [email protected]> wrote: > On Mon, Jan 30, 2017 at 3:08 PM, Cosmin Truta <[email protected]> > wrote: > > Advocating uncompressed-only EXIF is like advocating its applicability > > for conventional digital photography only. Although that's fine by me, > > Well., eh... yes? Right? Isn't that what I'm saying? It's a > standard developed by Japanese Digital Camera Manfactures, right? > CIPA: > > http://www.cipa.jp/ > > Right? > > I wouldn't do it this way if I was developing a file-format-neutral > meta-data format from scratch. I mean, TIFF, seriously? > > Nevertheless a file-format-independent metadata format has been > developed and successfully marketed by CIPA; it is a fait accompli, a > thing that has been done. I don't understand why this is an argument against compression. The Exif profile is some baggage that comes with JPEG images. When we convert a JPEG to PNG (or JNG) we preserve that baggage. Why not compress it? We're not inventing a new format, just inventing a way of storing that info. I don't buy the argument that it's not worth while because it is so small. Generally the first thing I do with photos is to scale them down to some reasonable size that will fit on my screen, so now they are usually about 1Meg not 100Meg, but the Exif profile stays the original size. Consider the files at www.simplesystems.org/users/glennrp/eXIf/nikon_b700 The Exif profile is 24945 bytes. The JPEG is 385520 bytes, including the Exif profile. The Exif profile in a ziXf chunk is... hey, the zxIf examples are missing, but it was about 10k. So in this (typical for me) case, the savings is 15k/385k, or about 4% I'll upload the zxIf results again later today. As a fraction of the PNG files, yes it's tiny, 15k/8M, or 0.2% ------------------------------------------------------------------------------ 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