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

I thought about this further...

Apart from including ICC profiles, our best option to communicate grayscale in a scientifically unambigious way,

Have someone seen a ICC profile, a EXIF object, a BROUZOUF object, make something else than adding ambiguity? ( Don't say waste CPU cycles and RAID cylinders, I know ) :-)))

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.

Understand, that for this... scope of image description, I have more questions than answers.

I have not asked cause, at this point, and for some days, I'm involded under this level, with "raw" process of tifftif, to that tiff's part of colorspace/pixeldepth/signed-unsigned managemenent can be handled the same than for "line" process.

A point is that, for example, CIELAB ( photometric 8), might ama be handled in some way similar to JPEGCOLORRGB.... What you say is quite some level more, cause it may involve all COMPRESSSION_xxxx, not only jpeg.

Jean-Yves