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TIFF and LibTiff Mail List Archive

Thread

2006.09.22 01:07 "[Tiff] Status of ISO JBIG and CIELAB JPEG support", by A Wandering LibTIFF User
2006.09.22 11:14 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme
2006.09.26 06:48 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by A Wandering LibTIFF User
2006.09.26 10:48 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Jean-Yves Le Ridant
2006.09.26 11:56 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by A Wandering LibTIFF User
2006.09.26 12:50 "Re[2]: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Jean-Yves Le Ridant
2006.09.26 17:53 "Re[2]: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Jean-Yves Le Ridant
2006.09.26 21:20 "RE: Re[2]: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Chris Cox
2006.09.26 23:25 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Jean-Yves Le Ridant
2006.09.27 06:13 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Graeme Gill
2006.09.26 14:02 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme
2006.09.26 13:38 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme
2006.09.27 12:38 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme
2006.09.27 19:42 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by A Wandering LibTIFF User
2006.09.27 20:39 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme
2006.09.28 18:39 "Re[2]: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Jean-Yves Le Ridant
2006.09.29 08:30 "Re[2]: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Jean-Yves Le Ridant
2006.09.29 12:50 "Re: Re[2]: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme
2006.10.03 11:26 "Re[4]: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Jean-Yves Le Ridant
2006.10.03 13:09 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme
2006.10.19 12:56 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by LERIDANT Jean-Yves
2006.09.27 20:12 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by A Wandering LibTIFF User
2006.09.22 13:55 "RE: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Ed Grissom
2006.09.25 17:08 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme

2006.09.29 12:50 "Re: Re[2]: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme

Jean-Yves,

I apologize for my previous post which is confusing.

No worries, I think we all understood what you meant. And I for one am the first to confirm live's hard on us non-native English speakers. ;-)

I've taken a closer look at your testimages. From the filenames, I can tell you have a great sense of humor.

Now as to the content... I'm not going to add my usual lengthy analysis for every file, since that would make this a multipage post, but enumerate only the few problem areas.

** dad_cie.tif **

This uncompressed 8bit CIELab file seems perfectly fine.

I note that you don't specify the Subsampling tag, and don't use subsampling inside the data. The combination of this should mean that you have the 'strict' view on subsampling, i.e. that it only applies to YCbCr.

** dad_icc_jpeg.tif **

This JPEG compressed 8bit ICCLab file seems perfectly fine.

I note that you DO specify the Subsampling tag, and the JPEG compressed data is indeed subsampled. The combination of this should mean that you have the 'wide' view on subsampling, i.e. that it applies to any color space with a first brightness channel and two chroma channels (YCbCr, CIELab, ICCLab, ITULab).

I'm not saying either of the above is incorrect, I'm not qualified to sort this out. But I am saying this is a problem area in TIFF, and your choice is not consistent.

** home16_cie.tif **

This uncompressed 16bit CIELab file seems perfectly fine.

No subsampling tag, no subsampling.

** home16_icc_jpeg.tif **

This is a JPEG compressed 16bit ICCLab file. That's no good. JPEG compression can be combined only with 8bit and 12bit per channel data. I feel the correct decoding response to this is an error message, and that's exactly what my decoder is doing.

** home16_jpeg.tif **

This is a JPEG compressed 16bit YCbCr file. That's no good. JPEG compression can be combined only with 8bit and 12bit per channel data. I feel the correct decoding response to this is an error message, and that's exactly what my decoder is doing.

** home16_none.tif **

This uncompressed 16bit RGB file seems perfectly fine.

** me_q50_s4x2.tif **

This JPEG compressed 8bit YCbCr file seems perfectly fine.

** mom_2x1.tif **

This JPEG compressed 8bit YCbCr file seems perfectly fine.

Funny, though, you seem to have a JpegTables tag in this file, and yet have JPEG tables in the single strip JPEG stream. That's OK, of course, the latter just override the first, but it's funny nonetheless seeing the detailed quality in your other files.

** qView.tif **

This JPEG compressed 8bit YCbCr file seems perfectly fine.

** source_tagged_ICC3507.tif **

This JPEG compressed 8bit ICCLab file seems... I've some remarks.

The colors are off, this is likely not ICCLab at all. Inside the single strip JPEG stream, there's an APP1 marker that should not be there, as well as a DNL marker. Despite of the DNL marker, the image length seems to be properly encoded inside the SOF0 marker.

Thus, this file much ressembles the fax000... bugzilla attachement that we started out with in this lengthy thread. I guess you're probably aware of that? Just make sure people don't mistake it for a valid testfile.

** Tiff_Spec_6.7_revA_approved_by_major_leading_companies.tif **

This JPEG compressed 8bit YCbCr file seems perfectly fine.

I didn't know there were this many major leading companies interested in approving a new TIFF specification. ;-)

Best regards,

Joris