1999.06.21 06:31 "Re: 64-bit TIFF Meta-issues", by Niclas Borlin

Well, Niles, couldn't we use your xtiff code for this? (At least if we can't persuade Adobe to join?)

Simplistic suggestion:

• Use any tag number (I could donate one of mine), call it TIFFTAG_TIFF64.
• Place a TIFFTAG_TIFF64 tag in the first IFD of a 6.0 TIFF file, and use the TIFF_LONG value as a file offset to a TIFF64 structure. This structure we could define ourselves, including new types, etc., even if Adobe holds back.
• The image data associated with the first IFD could hold the image data proper (if <4GB), be used as a "thumbnail", or have an image stating "This is a TIFF64 image >4GB. In order to view this image, you will need to update your TIFF reader from www.tiff.org (or whereever)."

This solution would at least be backward compatible, since older readers would ignore the TIFFTAG_TIFF64 tag...

I have used a similar (yet 32 bit) solution to include some patient/examination data, scanner settings, etc., in my TIFF files.

My .02 [your currency goes here].

/Niclas
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Niclas Borlin                       email: Niclas.Borlin@cs.umu.se
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