Re: CALL for DISCUSSION: eXIf 20170115
John Bowler <[email protected]>
| Newsgroups | gmane.comp.graphics.png.general |
|---|---|
| Message-ID | <CAP7U39_6zM5CVxW0KQWWs4BZE=JPLARwzWXwGwvE1er9v6741A@mail.gmail.com> |
On Mon, Jan 30, 2017 at 7:41 PM, Willem van Schaik <[email protected]> wrote: > > meant to say ... > > EXIF chunk of 100k versus 50k in a 10 MB image file ?? The maximum chunk size we will see from digital cameras is 64kbyte, because this is the size JPEG restricts the chunk to (CIPA 2016 makes this observation). The reason EXIF can be compressed at this point is because the manufacturers haven't exceeded that limit; what I was compressing was "padding" (up to 2006 bytes) and the MakerNote; more pixels more MakerNote. Once they hit the 64k limit (this will happen) they will compress, or rather encode more efficiently, the MakerNote and reclaim the padding. If anyone starts generating EXIF ab-initio (without starting from a DCIM) any MakerNote (any undocumented application specific data) they generate will be up to them and they probably won't include "padding". -- John Bowler <[email protected]> +1 (541) 450-9885 PO BOX 3151 KERBY OR 97531-3151 USA ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot