2001.10.10 16:18 "Palette TIFFs", by Eric Chamberlain

2001.10.10 21:00 "Re: Palette TIFFs", by Frank Warmerdam

I am struggling to display a Palette TIFF. My example has ExtraSamples=1 (generated by Illustrator).

So far, I seem to have about half the image displaying correctly. The parts that are not displaying correctly seem to be color-related (rather than positional) so I think the problem may be in the color section. Does ExtraSamples affect the ColorMap? If so, how?


Well, if the extra sample isalpha transparency values then it could have an effect. It would be helpful for you to supply a "tiffinfo" report on the file you are having problems with.

You might also look at using the TIFFReadRGBAImage() API if you aren't already. It can simplify handling of some issues like alpha blending and odd color models.

Also, I have tried to hook up with the LIBTIFF CVS library (anonymous@remotesensing.org:/cvsroot )and cannot connect to it. I have the CVS client software (WinCVS) but could get through. If you have been able to, please let me know! Looking at that stuff would be really nice right about now.

Keep in mind that you need to login with the password "anonymous". It seems to be working fine for me when I tested a couple minutes ago. Are you behind a firewall? This will defeat "pserver" style CVS access sometimes.

Best regards,

I set the clouds in motion - turn up   | Frank Warmerdam,  warmerdam@pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent

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