1997.05.23 06:12 "CCITT Grp 4 - uncompressed data", by Robert Pelcak

1997.05.23 06:12 "CCITT Grp 4 - uncompressed data", by Robert Pelcak

After having gotten the most recent version of the TIFF library (tiff-v3.4beta036), we have found that several of the graphics in our graphic lib no longer work when converted to postscript. The graphics all have in common CCITT Group 4, min-is-white, Group 4 options: uncompressed data.

We tested those graphics with the most recent version of "xv", which uses an older version of libtiff, and they work fine with that. (xv uses v3.3beta016).

Using tiff2ps with the new library produced (among *many* others) the eror message "Fax4Decode:... Uncompressed data (not supported)... ". Inspection of the source code in tif_fax3.c showed that:

  1. The encode/decode algorithm has been completely re-done, to one "derived from Frank Cringle's viewfax";
  2. The current code most certainly does not support the uncompressed data option for CCITT Group 4.

Why is this option no longer supported?

Is there anything that we can do so that we can handle CCITT Group 4 graphics using that option?

Thank you for any help you can provide.

Bob Pelcak
Xyvision, Inc.
Robert Pelcak
pelcak@xyvision.com