AWARE SYSTEMS
TIFF and LibTiff Mail List Archive

2004.09.16 22:39 "[Tiff] Re: BigTIFF Tag Value Count issue", by Ian Ameline

Photoshop stuffs an entire .PSD file into one tag effectively. And while the length fields in PSD are 4 bytes, there are several sections of a PSD concatenated together, each of which could be 4 Gig. I doubt that Photoshop could read such a file, however, making the whole topic academic.

But it does feel like making the tag length field 4 bytes might be one of those things that, down the road, leads to a call for an "EvenBiggerTIFF" spec.

While I don't store strips or tiles that large, and probably never will, it does make sense for the strip and tile size to be able to be large. Obviously all offsets within the tiff file, including SUBIFD offsets must be 8 bytes.

--
Regards,
Ian Ameline,

Software Architect,
Alias SketchBook Technical Lead.

-- Always do the right thing. This will gratify
some people and astonish the rest. -- Mark Twain.