Grayscale image: Difference between revisions

Use the function rgb-to-gray-image to convert a rgb-image as loaded by the function defined [[Bitmap/Read reada ppm file#Common Lisp]]. The package identifier assumes that you have the packeagepackage as defined in [[Basic bitmap storage#Common Lisp]]. With the function grayscale-image-to-pgm-file it is possible to write out the gray image as pgm file which can then be further processed.