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 tiff2bw − convert a color TIFF image to greyscale  | 
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 tiff2bw [ options ] input.tif output.tif  | 
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 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.  | 
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 −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).  | 
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 −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.  | 
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 −R  | 
 Specify the percentage of the red channel to use (default 28).  | 
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 −G  | 
 Specify the percentage of the green channel to use (default 59).  | 
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 −B  | 
 Specify the percentage of the blue channel to use (default 11).  | 
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 pal2rgb(1), tiffinfo(1), tiffcp(1), tiffmedian(1), libtiff(3) Libtiff library home page: http://www.simplesystems.org/libtiff/  |