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January 2004
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2004.01.23 19:19 "Re: How to convert MINISBLACK to PHOTOMETRIC_RGB", by Bob Friesenhahn
On Fri, 23 Jan 2004, Frank Warmerdam wrote: > > I am by no means an authority on the TIFF specification. My interpretation > of the file in question is that a sensible application should render the > first band in greyscale and ignore the 2nd and 3rd since they are extra samples > with no meaning attached. Without the ExtraSamples tag, I think an application > should assume the file contains 3 greyscale bands which might be drawn in any > number of ways. One way would be to draw 1 band, and give the user the ability > to flip through to see the 2nd and 3rd. Another would be to just treat them > as RGB (as many multispetral imaging packages will do with the first 3 bands > of multispectral data). I am no TIFF authority either. I aggree with your summary. The extra samples could mean almost anything. More than likely the correct intepretation of the extra samples depends on the vendor extension tags that libtiff warned about. :-) Bob ====================================== Bob Friesenhahn bfriesen@simple.dallas.tx.us http://www.simplesystems.org/users/bfriesen