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2005.05.25 09:52 "[Tiff] How to Write a tif file with compression = COMPRESSION_JPEG & photometric = PHOTOMETRIC_YCBCR ?", by Kelvin Zhong
2005.05.25 10:41 "Re: [Tiff] How to Write a tif file with compression = COMPRESSION_JPEG & photometric = PHOTOMETRIC_YCBCR ?", by Jean-Yves Le Ridant
2005.05.26 01:50 "Re: [Tiff] How to Write a tif file with c ompression = COMPRESSION_JPEG & photometr ic = PHOTOMETRIC_YCBCR ?", by Kelvin Zhong
2005.05.26 08:37 "Re[2]: [Tiff] How to Write a tif file with compression = COMPRESSION_JPEG & photometric = PHOTOMETRIC_YCBCR ?", by Jean-Yves Le Ridant
2005.05.26 10:02 "Re[2]: [Tiff] How to Write a tif file wit h compression = COMPRESSION_JPEG & photom etric = PHOTOMETRIC_YCBCR ?", by Kelvin Zhong
2005.05.26 12:24 "Re[3]: [Tiff] How to Write a tif file with compression = COMPRESSION_JPEG & photometric = PHOTOMETRIC_YCBCR ?", by Jean-Yves Le Ridant
2005.05.26 13:03 "Re: Re[3]: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG & photometric = PHOTOMETRIC_YCBCR ?", by Joris Van Damme
2005.05.26 14:10 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG & photometric = PHOTOMETRIC_YCBCR ?", by Jean-Yves Le Ridant
2005.05.26 16:23 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Joris Van Damme
2005.05.26 16:50 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Bob Friesenhahn
2005.05.26 17:00 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG&photometric = PHOTOMETRIC_YCBCR ?", by Joris Van Damme
2005.05.26 19:30 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Chris Cox
2005.05.26 19:34 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Bob Friesenhahn
2005.05.26 19:41 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Chris Cox
2005.05.26 19:38 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Chris Losinger
2005.05.26 19:43 "[Tiff] Re: Byte Order rules", by Chris Cox
2005.05.26 19:48 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Bob Friesenhahn
2005.05.28 18:01 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Joris Van Damme
2005.05.30 09:42 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Jean-Yves Le Ridant
2005.05.30 10:31 "Re: [Tiff] How to Write a tif file with compression=COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Marti Maria
2005.05.30 13:04 "Re: [Tiff] How to Write a tif file with compression=COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Jean-Yves Le Ridant
2005.05.30 14:39 "Re: [Tiff] How to Write a tif file with compression=COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Marti Maria
2005.05.31 18:36 "Re: [Tiff] How to Write a tif file with compression=COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Chris Cox
2005.05.31 18:35 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Chris Cox
2005.05.31 18:54 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Bob Friesenhahn
2005.05.31 19:00 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Chris Cox

2005.05.28 18:01 "Re: [Tiff] How to Write a tif file with compression =COMPRESSION_JPEG& photometric = PHOTOMETRIC_YCBCR ?", by Joris Van Damme

Jean-Yves,

In my humble opinion, if a multichannel colorspace start with a brightness channel, and the SamplesPerPixel value equals 1, that is a unambigious situation, and may be preferable over storing grayscale as full YCbCr.

Yes, but do this conform to TIFF specifications?

I thought about this further...

Apart from including ICC profiles, our best option to communicate grayscale in a scientifically unambigious way, is probably by using the L* component of L*a*b*. If we were to say that Photometric=YCbCr and SamplesPerPixel=1 is not legit... I don't think we have a legit way to store L* rasters, either.

That may be a to pragmatic argument to be convincing, but I would like to add to that, again, that Photometric=YCbCr and SamplesPerPixel=1, or Photometric=whateverLab and SamplesPerPixel=1 is really unambigious. I would hesitate to write it, for now, unless people here clearly indicate they feel the same about this as I do, but I would certainly think you'll need to be prepared to at least read it.

Joris Van Damme
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