Gimpshop question- format?

[bruce]

Hey does Gimpshop not like tiff files? I scanned a bunch of stuff, saved as tiff files. When I open them in Gimpshop they come out looking really grainy and awful.
 If gimp doesn't like tiff, what format should I be saving stuff in?

[ImageMaker]

One problem you might be seeing is that there are literally a dozen different versions of TIFF -- uncompressed, in IBM and Mac byte order, and a bunch of different compression schemes ranging from lossless Lempel-Ziv to JPG compression; I've seen precious few programs (not including GIMP) that can read all the different TIFF compression schemes.  Depending on the source of the TIFF, you might be seeing a preview thumbnail that's been expanded -- or you might be seeing actual grain artifacting that wasn't visible in the scanning step.

FWIW, I save my raw scans as uncompressed TIFF -- makes huge files (20 MB for a color 35 mm at 2400 ppi), but everything can read 'em.  Of course, now the drive I store those on is full and I have to perform computer surgery and install the 200 MB drive I currently have in another machine before I can scan any more film...

[jmi]

Just to add one thing here - the fast scaling algorithm Gimp uses for the image display does tend to do this sometimes, if you feed in a big scan that has already had USM applied.  Try viewing 1:1 (in the Gimp you just hit the 1 key, not sure about this version).  It may look OK there, or indeed after you have scaled the image down to the final size, which is the normal interpolated algorithm.  However you've probably already done this...

[bruce]

I think the problem is Gimp is reading the thumbnails. I am using the Nikon Scan software, and I can't figure out how to turn the thumbnail off when saving the file.
 Or is there a way to make gimp ignore the thumbnail?

[ImageMaker]

I've never seen GIMP read only the thumb -- and besides, that would look pixellated, rather than grainy.  However, I long ago gave up trying to import (say, from PS5LE that I use for scanning because it can scan at 16 bits per channel) in any format other than uncompressed TIFF at 8 bits per channel.