How to compress image data within a postscript file.

Dear all

I need to work with Postscript format, but usually this format generates very large file in comparision of native files, specially for image files.

I have tried to compress the file using many compression(like zip,bz2 etc), but these compressions does not provide a useful difference btw the file sizes.

I am looking follwing type of solutions

1. Creating postscript file in which all images are in compressed format.
2. Any utility/Software by which I can compress the image data within the postscript file.
3.Any otner compression format by which i can compress whole postscript file and can get a small PS file in comparision to original PS file.

Regards
Shobhit Jain