2005.10.12 12:11 "[Tiff] how to update tiled YCbCr JPEG image?", by Шебеко Евгений

2005.10.13 14:32 "Re: [Tiff] how to update tiled YCbCr JPEG image?", by Joris Van Damme

Maybe it because JPEG Tables are changed too?

I'm not sure I understand correctly...

Normally, usually, if the JpegTables tag is there, the tiles contain jpegs without tables. So you could try replacing a single tile with another jpeg without tables, making sure, of course, that the tables this jpeg logically uses are the ones mentioned in the tables-only-jpeg in the JpegTables tag.

The way I read the jpeg-in-tiff specification, it should however be legal to include a jpeg with tables in a tile, even if the JpegTables tag is there. This should be interpreted by letting the tables in the tile jpeg take precedence over the tables in the JpegTables jpeg. This should not interfere with the decoding of other tiles.

This is, however, an unusual situation, and it may be that LibTiff does not respond to it properly.

This is all a wild guess, though, I'm not even sure I understand your problem correctly.

If you're able to reproduce your problem in a suitable small file (like 1 megabyte at most), you can send it to my personal e-mail address, together with a good description of what you think the image should look like, and I'll try and investigate the file and see if I can confirm.

Joris Van Damme
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