REBOL [ Title: "Image to pgm converter" Date: 19-Jan-2013 File: %oneliner-image-to-pgm.r Purpose: "Creates a binary Portable Graymap (PGM - P5) from an image! source" Version: 1.0.0 Author: "Vincent Ecuyer" Usage: { to-pgm value (image!) channel ('r, 'g, or 'b) alpha-to-pgm value (image!) ==REBOL2 write/binary %imageTest-red.pgm to-pgm logo.gif 'r write/binary %imageTest-green.pgm to-pgm logo.gif 'g write/binary %imageTest-blue.pgm to-pgm logo.gif 'b write/binary %imageTest-alpha.pgm alpha-to-pgm logo.gif ==REBOL3 write %imageTest.pgm to-pgm make image! [320x256 127.0.0] 'r } Comment: { The result is in PGM P5 (binary) format, compatible with Gimp, Netpbm tools, and other image processing packages. The 'alpha-to-pgm function can be used with 'to-ppm to save the transparency/alpha channel (as there is no alpha information in a .ppm file). } Library: [ level: 'intermediate platform: 'all type: [tool one-liner function] domain: [graphics] tested-under: [ view 2.7.8.3.1 on [Windows win32-x86] core 2.101.0.2.5 on [Macintosh osx-x86] ] support: none license: 'public-domain see-also: %oneliner-image-to-ppm.r ] ] to-pgm: func [value [image!] channel [word!]] [join #{} ["P5 " replace form value/size "x" " " " 255^(0A)" extract/index value/rgb 3 index? find [r g b] channel]] alpha-to-pgm: func [value [image!]] [join #{} ["P5 " replace form value/size "x" " " " 255^(0A)" value/alpha]]