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
Thread
1997.01.14 11:08 "Problem with CCITT G4 and long scanlines", by Mogens Sorensen
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 ?). I am generating the tiff file with the library and then use tiffinfo -D to check it. For most files tiffinfo gives a lot of errors and warnings, for others it tries to access an illegal address and exits. I do not know the inner working of the G4 compression/decompression code/algorithm and have therefore not tried to debug it yet. Has anybody seen similar problems or know about limitations ?, and possibly made a fix for it ? The following dump shows the errors I get as well as details about the file format. tiffinfo -D 2380001.tif TIFF Directory at offset 0xc16a02 Image Width: 119104 Image Length: 24765 Resolution: 2540, 2540 pixels/inch Bits/Sample: 1 Compression Scheme: CCITT Group 4 Photometric Interpretation: min-is-white Orientation: row 0 top, col 0 lhs Samples/Pixel: 1 Rows/Strip: 16 Planar Configuration: single image plane Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 0 (got 119136, expected 119104). Fax4Decode: 2380001.tif: Bad code word at scanline 13 (x 118748). Fax4Decode: Warning, 2380001.tif: Premature EOL at scanline 13 (got 118748, expected 119104). Fax4Decode: 2380001.tif: Bad code word at scanline 14 (x 1052). Fax4Decode: Warning, 2380001.tif: Premature EOL at scanline 14 (got 1052, expected 119104). Fax4Decode: Warning, 2380001.tif: Premature EOF at scanline 15 (x 53568). Fax4Decode: Warning, 2380001.tif: Premature EOL at scanline 15 (got 53568, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 16 (got 120036, expected 119104). Fax4Decode: 2380001.tif: Bad code word at scanline 30 (x 59342). Fax4Decode: Warning, 2380001.tif: Premature EOL at scanline 30 (got 59342, expected 119104). Fax4Decode: 2380001.tif: Bad code word at scanline 31 (x 1052). Fax4Decode: Warning, 2380001.tif: Premature EOL at scanline 31 (got 1052, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 32 (got 120036, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 48 (got 128262, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 64 (got 128261, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 80 (got 128261, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 96 (got 128261, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 112 (got 128261, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 128 (got 128261, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 144 (got 128261, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 160 (got 128261, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 176 (got 128261, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 192 (got 119517, expected 119104). Fax4Decode: Warning, 2380001.tif: Line length mismatch at scanline 193 (got 119106, expected 119104). Fax4Decode: 2380001.tif: Uncompressed data (not supported) at scanline 194 (x 4678). Fax4Decode: Warning, 2380001.tif: Premature EOL at scanline 194 (got 4678, expected 119104). ............. Regards Mogens ------------------------------------------------------------------ ! PURUP ESKOFOT A/S ! Phone........: +45 8743 4343 ! ! Mogens Sorensen, R&D ! Phone direct.: +45 8743 4372 ! ! Sonderskovvej 5 ! Fax..........: +45 8743 4445 ! ! DK-8520 Lystrup, DENMARK ! E-mail.......: ms@pe.dk ! ------------------------------------------------------------------