The TIFF versus JPG debate

My $0.02 worth on the abovementioned subject: TIFF has lots of ways data can be encoded within the basic TIFF file structure, including LZW, CCITT G3 and CCITT G4 formats. If anyone is interested, get a good look at the TIFF V6 specification, although the links on the www.libtiff.org site seem to be broken and Adobe has now put their copy of the TIFF specification behind a whole lot of "developer registration required" pages you need to get through first. See also http://www.awaresystems.be/imaging/tiff/tifftags/compression.html which describes the TIFF tags relating to compression of image data. bitonal (black and white only) image documents for 150,000 engineering drawings with excellent results. This is a totally lossless compression format (what you get back is exactly what you put in) specifically designed to do a good job with what you'd find on pages of drawings or of text. If you don't need colour or greyscale, then CCITT G42D is hard to beat. Within the US military, the CALS (Computer-aided Acquisition and Logistics Support) Type 1 specification for bitonal images basically wraps the compressed CCITT G42D data inside a slightly different wrapper to TIFF - CALS is a fixed length text header, and TIFF is a lot of binary stuff. It's easy to convert between the two formats when you know how. What I like about TIFF coupled with CCITT G42D compression most is (a) it's lossless, (b) supports multi-page documents, (c) it's an open specification with (d) an open source library to manipulate the files (LIBTIFF) and (e) it is widely supported with hundreds of viewers available (on Windows, the free Imaging component works fine for most people). I can also easily transform my TIFF data into Postscript (btw Level 2 Postscript more or less supports CCITT G42D compression too), PCL or even into PDF with not too much drama. In comparison, PDF is locked in more or less to Adobe's Acrobat Reader (yes, I know there's always Ghostscript / GSView and friends ! ), and not as easy to manipulate - I call it more of a nearly "final form" document format than TIFF. JPEG is not suitable because it was a lossy format targeted at colour images more than black and white, and it wasn't multi-page. I believe the JPEG 2000 specification has improved on some of these such as providing a lossless compression option, and can handle multi pages. I don't know if software to support all these features is (a) cheap or (b) available. For my money, I'm sticking with TIFF Cheers Jason