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
October 2005

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

2005.10.12 12:11 "how to update tiled YCbCr JPEG image?", by Eugene Shebeko
2005.10.13 14:32 "Re: how to update tiled YCbCr JPEG image?", by Joris Van Damme
2005.10.13 17:39 "Re: how to update tiled YCbCr JPEG image?", by Eugene Shebeko
2005.10.14 15:58 "Re: how to update tiled YCbCr JPEG image?", by Joris Van Damme

2005.10.14 15:58 "Re: how to update tiled YCbCr JPEG image?", by Joris Van Damme

Шебеко Евгений wrote:
> But I try same with tiled image with JPEG YCbCr compression but
> without JpegTables tag in source file - it work fine.

I'm not sure how to explain it.

From what I've read (but I've not currently the time to reproduce and I
might be mistaking), and from the screenshots you've sent about another
file, it seems like LibTiff may be handling the case where there's a
JpegTables tag and tables in the jpeg compressed tile wrong. What it
should do, is let the tables in the tile take precedence for that tile
only, and restore to the JpegTables state before decoding any other
tile.

> Then I try to update striped image with JPEG YCbCr compression and
> JpegTables tag but it not work at all. I have an assert error at:
>
> tif_jpeg.c:1248        assert(!sp->cinfo.comm.is_decompressor);

This also may be a bug.

I'm sorry I can't help any further. I'm not a LibTiff maintainer, my
main area is just the file format, not the library. You're best bet is
to wait for Frank and/or Andrey to confirm, and/or add an entry in
BugZilla.


Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
Download your free TIFF tag viewer for windows here:
http://www.awaresystems.be/imaging/tiff/astifftagviewer.html