AWARE [SYSTEMS] Imaging expertise for the Delphi developer
AWare Systems, Imaging expertise for the Delphi developer, Home TIFF and LibTiff Mailing List Archive

LibTiff Mailing List

TIFF and LibTiff Mailing List Archive
November 2000

Previous Thread
Next Thread

Previous by Thread
Next by Thread

Previous by Date
Next by Date

Contact

The TIFF Mailing List Homepage
This list is run by Frank Warmerdam
Archive maintained by AWare Systems



Valid HTML 4.01!



Thread

2000.11.29 14:18 "more G4", by <apex@apexinternetsoftware.com>
2000.11.29 18:44 "Re: more G4", by Joel Schumacher
2000.11.29 18:50 "Re: more G4", by <apex@apexinternetsoftware.com>

2000.11.29 14:18 "more G4", by <apex@apexinternetsoftware.com>

Hi,

I get some images from a "Life*ODIN" system that are not being read by
the libtiff code, nor by other programs, for example Kodak Imaging.
This is only some, not all of the files from them.  This is using
libtiff-3.4beta037.

These images purport to GroupIV TIFF.  They are structurally sound TIFF
files, but the Group IV data is being illegible.  The libtiff decoder is
able to get from the single image data strip the upper portion of the
data, for example the first couple hundred scan lines, the rest is
blank.

There is a "Fax4Decode Warning" emitted, it says "R136711.TIF: Premature
EOL at scanline 864 (got 1581, expected 3323)".  Then another,
"R136711.TIF: Premature EOL at scanline 865 (got 0, expected 3323)".
This continues:

scanline 866(got 0, expected 3323)
scanline 867(got 0, expected 3323)

Then there is another warning for each remaining scanline in the image.

The images have two private tags, 34645 (0x8755) and 34646 (0x8756)

So, I go to Fax codec and see where this is emitted, to see if I can get
it to skip the special case and extract the bulk of the image data.  So
I go to tif_fax3.c.  This warning is kicked off by the function
Fax3BadLength. Fax3BadLength is defined into the badlength macro.  I
define FAX3_DEBUG and recompile.  Now it is providing considerably more
verbose output as it decompresses.

On a separate note, can anyone say what softwares use the page numbering
system, that is to do with TIFFTAG_PAGENUMBER?

Thank you,

Andy
--
contact Andy
company Apex Internet Software
email info@apexinternetsoftware.com
website http://www.apexinternetsoftware.com/