Convert a color tiff image to greyscale
tiff2bw [ options ] input.tif output.tif
Tiff2bw converts an RGB or Palette color TIFF image to a greyscale image by combining percentages of the red, green, and blue channels. By default, output samples are created by taking 28% of the red channel, 59% of the green channel, and 11% of the blue channel. To alter these percentages, the -R, -G, and -B options may be used.
-c
Specify a compression scheme to use when writing image data: -c none for no compression, -c packbits for the PackBits compression algorithm, -c zip for the Deflate compression algorithm, -c g3 for the CCITT Group 3 compression algorithm, -c g4 for the CCITT Group 4 compression algorithm, and -c lzw for Lempel-Ziv & Welch (the default).
-r
Write data with a specified number of rows per strip; by default the number of rows/strip is selected so that each strip is approximately 8 kilobytes.
-R
Specify the percentage of the red channel to use (default 28).
-G
Specify the percentage of the green channel to use (default 59).
-B
Specify the percentage of the blue channel to use (default 11).
pal2rgb(1), tiffinfo(1), tiffcp(1), tiffmedian(1), libtiff(3)
Libtiff library home page: http://www.remotesensing.org/libtiff/