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2008.03.29 11:44 "Re: 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: > On Sat, 29 Mar 2008, James Sumners 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. > > Bob > ====================================== > Bob Friesenhahn > bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ > GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ > > -- James Sumners http://james.roomfullofmirrors.com/ "All governments suffer a recurring problem: Power attracts pathological personalities. It is not that power corrupts but that it is magnetic to the corruptible. Such people have a tendency to become drunk on violence, a condition to which they are quickly addicted." Missionaria Protectiva, Text QIV (decto) CH:D 59