2010.02.08 10:47 "[Tiff] fftw and TIFF files", by

2010.02.10 17:43 "[Tiff] Using tiffcmp for comparing images", by Richard Nolde

Debora,

I believe that you can use the -l option to tiffcmp to contine past the first differing byte and generate a list of all the bytes that differ. You can pipe that output to wc and see how many words/lines/bytes have been reported to get a gross estimate of the number of difference bytes and test that against a threshold you determine empirically if that meets your needs.

tiffcmp could be useful if it didn't stop when it finds the first difference between the files. What if there is only one pixel different? for the person that reads the fax it should be imperceptible. Only one, or two... or maybe a hundred pixels shouldnt be a problem depending on the content of the image. That's why I need to compare all the data. You made a good poing though. Thank you so much.

Debora

  From the tiffcmp man page:

NAME
        tiffcmp - compare two TIFF files

By default, tiffcmp will
terminate if it encounters any difference.

OPTIONS
        -l List each byte of image data that differs between the files.