| tiff2bw − 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/ |