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Re: TIFF Read/Write Bug? [message #84242]

Sun, 12 May 2013 07:08

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

Tom Grydeland writes:

> The description of palette images is in section 5. For palette images, the number of bits per sample can be 4 or 8, corresponding to 16 or 256 colors (the color values are short integers, however, giving 65536 levels for each of red, blue and green at each index). For more colors than that, you must go to one of the RGB full color modes.

Yes, I think my mistake was treating TIFF images as if they were netCDF
or HDF files. I had classified data in the byte range, but I wanted to
store "missing" data with the value -999, which was why I was using an
integer array. At the same time, I didn't want to lose the color vectors
that "explained" the data.

Of course, when you store "color" images in TIFF files, it is difficult,
if not impossible, to retrieve the science information. What I should
have used, of course, is a netCDF file where I can store the palette
information separately from the data itself. Unfortunately, netCDF files
are just much more difficult for my client to handle as she likes.

There are ways to work around the "problem", but some documenation that
the problem exists, in a location where I was likely to read it, would
have helped. :-)

Cheers,

David

--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
Sepore ma de ni thue. ("Perhaps thou speakest truth.")

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[Message index]

		Re: TIFF Read/Write Bug? By: David Fanning on Sun, 12 May 2013 07:08
		Re: TIFF Read/Write Bug? By: tom.grydeland on Sun, 12 May 2013 04:03
		Re: TIFF Read/Write Bug? By: Heinz Stege on Fri, 10 May 2013 16:04
		Re: TIFF Read/Write Bug? By: Phillip Bitzer on Fri, 10 May 2013 14:29
		Re: TIFF Read/Write Bug? By: David Fanning on Fri, 10 May 2013 14:08
		Re: TIFF Read/Write Bug? By: David Fanning on Fri, 10 May 2013 13:48
		Re: TIFF Read/Write Bug? By: Phillip Bitzer on Thu, 09 May 2013 07:37
		Re: TIFF Read/Write Bug? By: Heinz Stege on Wed, 08 May 2013 15:19

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