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June 2010

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2010.06.11 21:39 "Class Y images with alpha channels", by Thomas Richter
2010.06.11 23:26 "Re: Class Y images with alpha channels", by Bob Friesenhahn
2010.06.14 05:59 "Re: Class Y images with alpha channels", by Joris Van Damme
2010.06.14 06:36 "Re: Class Y images with alpha channels", by Thomas Richter
2010.06.14 07:51 "Re: Class Y images with alpha channels", by Joris Van Damme
2010.06.14 14:57 "Re: Class Y images with alpha channels", by Bob Friesenhahn

2010.06.14 05:59 "Re: Class Y images with alpha channels", by Joris Van Damme

Thomas,

> is there a possibility to add an alpha channel to a class Y (YCbCr) tiff
> image? I don't see this in the rev.6 specs.

Nor does the spec mention 12 bit per channel YCbCr, nor does the spec 
mention RGB with alpha and two unspecified channels, nor does it mention 20 
bit per channel grayscale, etc. We ought to understand the 'class' concept 
in the spec as a (misleading) enumeration of 'typical usage', whilst the tag 
system makes perfect sense as to allow just any variation.


Best regards,

Joris