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
January 1997

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

1997.01.14 11:08 "Problem with CCITT G4 and long scanlines", by Mogens Sorensen
1997.01.14 15:51 "Re: Problem with CCITT G4 and long scanlines", by Frank D Cringle
1997.01.15 17:32 "Re: Problem with CCITT G4 and long scanlines", by Mogens Sorensen

1997.01.14 15:51 "Re: Problem with CCITT G4 and long scanlines", by Frank D Cringle

Mogens Sorensen <ms@pe.dk> writes:
>I am using v3.4beta35 on WinNT and have run into some problems with Group 4
>compression when the scanline width exceeds 65536 pixels (16 bits ?).

Decompression, for G3 and G4, is handled by tif_fax3.[h,c].  There is
a built in assumption that uint16 is sufficient to hold a run-length.
So decompression certainly won't work with >65535 pixel lines.  If you
change most occurrences of uint16 to uint32 in those 2 files it might
work.  Most?  Well, all except the one in typedef struct TIFFFaxTabEnt
in tif_fax3.h, I guess.  This is from a very brief eyeballing of the
code.  I haven't tried it and I don't have time to get involved.
Sorry.

-- 
Frank Cringle,      fdc@cliwe.ping.de
voice: (+49 2304) 467101; fax: 943357