1993.09.26 21:12 "Help needed with tiff files...", by Manavendra Misra

Hi! I am having some problems in handling color-maps in tiff files, and was hoping that someone more experienced would be able to help me. I am trying something very simple--reading in a tiff file created by Imagetool (under Openwin 3.0, Solaris 2.2), and writing it out into another tiff file (just to test that I am able to read and write tiff files...). I am using Sam's libtiff functions to do so. The file I am reading is a grayscale image, but Imagetool stores it with color map info. After I have read it in my program, and written it out to a new tiff file, and I do a tiffinfo on it, I get:

choma% tiffinfo scaled.tif
scaled.tif: TIFF directory is missing required "Colormap" field.

Of course, I can't display the file using Imagetool.

The question is: how do I read the colormap field, and write it into the new file (I was able to read all the fields with a single parameter using the TIFFGetField, and was able to write them using TIFFSetField, but couldn't figure out a way to do so with multi-parameter fields)?

Another (slightly unrelated) question: I was looking for a tool for scaling an image. Has anyone written such a program? Even more interesting would be a program that provides the user with flexibility to scale the x and y axis differently.

I hope I am not abusing this mailing list--that it is indeed meant for pusposes such as these.

Thanks for any help you can provide!

Manav.

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Manavendra Misra
Stratton Hall 419
Dept of Mathematical and Computer Sciences
Colorado School of Mines
Golden, CO 80401

Ph. (303)-273-3873
Fax. (303)-273-3278
email: mmisra@mines.colorado.edu

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