2007.07.03 18:37 "[Tiff] BigTIFF extension?", by Phil Harvey

2007.07.05 23:30 "Re: [Tiff] RE: Tiff Digest, Vol 38, Issue 16", by Craig Bruce

First, a BigTIFF file is distinct from a BigTIFF tool. Gary's comment that an existing TIFF reader can't read a BigTIFF file is correct. That's not the same as being able to read a ClassicTIFF file generated by a BigTIFF tool.

As a mitigating factor, the tools that would normally be used on such ginormous images will likely be the first ones to integrate support for BigTIFF. Joe Sixpack will probably never work with a bigger image than his 10-megapixel camera generates.

- let the tool decide, try, and rewrite if the tool guessed wrong initially (risk of time loss, but best compatibility result).

For images that are written without compression (which seems to be most of the ones I have seen in the GIS field), you can compute to the byte how big a TIFF file will be, if you really want to. I'm simply going to compute the number of uncompressed sample bytes and add a couple percent. Any other approach seems rather senselessly pedantic to me.

Also, people who process these ginormous images are likely to be power users who are readily able to get their hands on a get a tiff recoder (tiffcp?) and convert from a BigTIFF file to a ClassicTIFF file if the content indeed would fit into a ClassicTIFF.

Dr. Craig S. Bruce        | Ph 819-771-8303 x205 |             CubeWerx Inc.
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