tic98, also known as TIC, is an excellent image compressor for scanned documents. It's not as robust as it could be on 'file not found' or usage errors, so I made a few changes. The author, Stuart Inglis, is not contactable, so I'm posting the patches here and entering the project in unmaintained.sourceforge.net. If the website listed above is no longer there, then try this mirror of the important files.
diff against tic98-1.01These scripts entic98 and untic98 allow tic98 to be used as a filter in Unix pipes, giving it a reasonable default set of options. They require pip installed.