I posted that code here a couple of years ago. It only counts the number of images in a TIFF file, by counting the number of directory entries. To actually split the file, you would need to decode the chain of directory entries to locate the various parts of each image, then extract them and reformat each into the proper TIFF file format. It is certainly doable in Perl, and would also be reasonably fast since decompressing would be unnecessary. However the TIFF spec is a bit complex, so you would probably be better off using existing tools as already mentioned.