Rule of thumb for future designers of image formats: If your file contains Exif or XMP data, *DO NOT* have separate header fields redundantly holding data that could/should be in the Exif or XMP. That's just an invitation for them to contradict each other and cause chaos.
On Jan 30, 2015, at 11:58 AM, Larry Gritz <[email protected]> wrote: > This is what was confusing my terminology! > > In implementing the recent patch, I found that libjpeg was not reliable to > set the xDensity and yDensity and that in JPEG files I found in the wild, > they did not match anyway and the Exif ones tended to be sensible. So in > OIIO, I am relying on the Exif fields. In theory, these should be the same > thing, but in practice it looks like other apps I checked all honor the Exif, > if found, rather than what's found in the base JPEG header fields. > > > On Jan 30, 2015, at 11:55 AM, Nathan Rusch <[email protected]> wrote: > >> I just learned that JPEG may have its own separate (i.e. non-EXIF) tags for >> XDensity and YDensity, and that is may also have its own "resolution units" >> tag whose value is "dots per <linear unit>", all of which would certainly >> create an interesting conflict. >> >> Are these the values OIIO is currently looking at? >> >> -Nathan >> > > -- > Larry Gritz > [email protected] > > > > _______________________________________________ > Oiio-dev mailing list > [email protected] > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org -- Larry Gritz [email protected] _______________________________________________ Oiio-dev mailing list [email protected] http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
