The file contains an image which is to be processed in some standard way. The processed image is written out with the same name. Enter the file to process. The next command, which reads an image from the disk, uses the string substitution mechanism to insert the string FILE into the command. The following procedure reads an image from the raw data disk, processes it in some way, then writes it back out to disk into another directory specified by the observer.
Program stops when the observer gives a negative number or zero.
See the discussion for the OPEN and READ commands for more details on using text files.