"tim sewell" <postmantim3@myfairlyobviousspamtrapoptusnet.com.au> wrote > Tiff files can be saved with LZW compression, which is lossless. P.S. I have just run a simple test to see how much space is saved by using the LZW compression. I converted five scans from LDS films of parish registers, all 8497 kB uncompressed (2480*3507 pixels, 8bps greyscale) and all with significant background 'mess'. The compressed files range from 6309 kB to 7022 kB, averaging 6609 kB, or about 78% of original size. HTH, -- Tim S. (please delete myfairlyobviousspamtrap if you wish to reply directly)

On Tue, 23 Oct 2007 12:39:31 +1000, "tim sewell" <postmantim3@myfairlyobviousspamtrapoptusnet.com.au> wrote: > >"tim sewell" <postmantim3@myfairlyobviousspamtrapoptusnet.com.au> wrote > >> Tiff files can be saved with LZW compression, which is lossless. > >P.S. > >I have just run a simple test to see how much space is saved by using the >LZW compression. > >I converted five scans from LDS films of parish registers, all 8497 kB >uncompressed (2480*3507 pixels, 8bps greyscale) and all with significant >background 'mess'. > >The compressed files range from 6309 kB to 7022 kB, averaging 6609 kB, or >about 78% of original size. > >HTH, My experience with LZW compression of TIFF files is that the processing time costs me more than the extra file space. I'm basically talking high resolution photos though, not the type of image you'd likely archive for it's text. For documents that I've scanned and saved to CD, I've found that scanning to TIFF, then converting the TIFF files to a PDF document works really well. If the PDF is high enough quality, it's even possible to OCR the PDF file using OmniPage pro. The size of the TIFF files isn't really important, since they are only a temporary medium, and are erased after the PDF document is created. -- Charlie Hoffpauir http://freepages.genealogy.rootsweb.com/~charlieh/