imgtoicp converts and image imgfile, to ICP-format image components, icpfiles.
If imgfile is a color image, imgtoicp requires that three output icpfiles be specified, one for each of the Y, U, and V components of the image, in order. Otherwise, for grayscale images, only one icpfile is to be specified.
Note: converting from PGM or PPM format to ICP format implies simply converting integer pixels to floating-point values.