2008.11.21 18:49 "Re: [Tiff] 24 bit Color to 8 bit Palettized Conversion Utility (tiffcp enhancement/variation?)", by Bob Friesenhahn
I'm looking for a command line utility with a version that runs under Windows which can convert a 24 bit color TIFF image to an 8 bit palettized TIFF image. But I need something that works similar to tiffcp that does the processing without loading the whole image into memory at once. I am aware of the very useful GraphicsMagick and ImageMagick utilities, but they both load the whole image into memory, which can be quite slow and somewhat problematic for some of the extremely large images that I work with.
Did you try VIPS? VIPS is able to accomplish many things without loading the whole image into memory and it is usually quite fast. I don't know if its color reduction works without loading the whole image though since that would require a several-pass algorithm.
VIPS usage is more arcane than ImageMagick or GraphicsMagick, but it does succeed where other software falters.
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/