1997.04.29 13:27 "Group 4 Compression and 256 Colors", by Sanjay G. Prabhudesai

1997.04.30 07:34 "Re: Group 4 Compression and 256 Colors", by Iñigo López

I am new to this mailing list. I have a fundamental doubt about a TIFF format.

I have a 256 color image. I want to transfer the same in TIFF format using Group 4 compression. Is it possible?

As specified in the TIFF specifications, Group 4 compression technique is used for BILEVEL images. Does it mean that this type of compression can be used only if the image is Black/White?

Yes, as specified, group 4 compression works only for BILEVEL images. The algorithm would not make sense for color pictures. If you want to compress a 256 color image, you will do much better using LZW (be careful about copyrights) or DEFLATE compressions.