2004.05.18 17:47 "[Tiff] Recovering tiff faxes corrupted with 3.6.0", by Andrew McGill
I have attached two files, representative of a problem I currently have, following a software upgrade to libtiff 3.6.0 as included with SuSE Linux 9.0. I hope it is not inappropriate to post data files to this particular list:
- fax01492.tif - mangled from g3 format with libtiff 3.6.0
- fax01493.tif - the correct image, handled by with libtiff 3.6.1
I have tried a number of approaches to correcting the error, which I am guessing is the bit ordering in the header not matching the bit ordering in the data file.
I tried this...
tiffset fillorder msb-to-lsb fax01492.tif
Which is clearly not right, because it complains...
fax01492.tif: Can't open a compressed TIFF file with compression for update..
My problem here is I don't understand the nature of the corruption in the files, which makes it rather difficult to fix. I'm going to spend the evening hacking at tiffset, but I have a feeling it's going to be an uphill battle, since the program is not supposed to deal with corrupt file (or, for that matter generate them).
I have 50 of these files from we-are-not-quite-sure-who, but we know that half of them did not set their fax number on their sending system. Any help would be appreciated.