2012.04.24 19:19 "Re: [Tiff] YCbCr/JPEG issue in 4.0.1", by Even Rouault

Le mardi 24 avril 2012 18:44:18, Frank Warmerdam a écrit:

It sounds like you ought to file a ticket on this. It may be that the changed behavior is intentional. If the tag isn't really there but is deduced for processing it may be that it is not considered desirable to expose it as if it were really a tag.

http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf shows that the default value for YCbCrSubSampling is [2, 2], so it might be allowed not to write it. Reading quickly http://www.remotesensing.org/libtiff/TIFFTechNote2.html does not show any evidence that the tag is required if the subsampling is equal to the default value. But that's just my interpretation...