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

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

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
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