2008.03.29 04:18 "[Tiff] TIFFReadRawStrip buffer data type", by James Sumners

2008.03.29 11:44 "Re: [Tiff] TIFFReadRawStrip buffer data type", by James Sumners

Well, the image I'm reading is not compressed. So I thought the data would just be the integer color value of each pixel. If that is incorrect, how would I get that data? I want to be able to work with the color values for the pixels so that I can do my own compression.

On Sat, Mar 29, 2008 at 2:05 AM, Bob Friesenhahn <bfriesen@simple.dallas.tx.us> wrote:

If I supply TIFFReadRawStrip() with a buffer of type int, and read a grayscale image, I assume that each position in the buffer would be a value between 0 and 255, right? If so, then I'm a little confused about the debug output of my program[1]. It seems to be reading a ten

This is the description for TIFFReadRawStrip:

      TIFFReadRawStrip - return the undecoded contents of a strip
      of data from an open TIFF file

The term "undecoded" means that you get the raw data as it exists in the TIFF file, including being compressed with some sort of compression.

Maybe you mean to use TIFFReadEncodedStrip() instead?

Even with TIFFReadEncodedStrip() you will get uncompressed data packed according to the bits per sample, samples per pixel, planar configuration, and photometric of the file. So it could be 4 bits per sample (two samples per byte) which refer to a color in a colormap.

James Sumners

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