RE: ScannerRGB to WorkingSpaceRGB (rendering intents)
RE: ScannerRGB to WorkingSpaceRGB (rendering intents)
- Subject: RE: ScannerRGB to WorkingSpaceRGB (rendering intents)
- From: Roger Breton <email@hidden>
- Date: Wed, 11 Jul 2001 08:14:20 -0400
>
Joel wrote:
>
> The thing that irks me most about perceptual is that
>
> it performs gamut compression REGARDLESS of whether the
>
> image has out of gamut colors or not.
>
>
Fred commented:
>
> Simply another case to be made for the "Smart CMM".
>
>
Perhaps ... although one has to be careful.
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Currently, the amount of gamut compression (from perceptual rendering)
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depends entirely on the relative sizes of the source and destination
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spaces.
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>
If the amount of gamut compression varies depending on the image
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content, this can lead to unpredictable behavior. One solitary pixel
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could concievably change the amount of gamut compression *dramatically*.
>
So, Fred, if I convert from a super-duper large RGB gamut like ROMM RGB or
Joe Holmes Ekta RGB on down to a tiny-wheeny Newsprint gamut, you see a
larger compression taking place as compared to Glossy Coated gamut?
What if the starting XYZ colors are well within the Newsprint gamut, will
the colors still get compressed by the Perceptual algorithm?
And what if I convert from my scannerRGB to EktaRGB, then, I do not get any
compression? Because these two gamuts are more or less the same "size"?
--
Roger Breton
Quibec Institute of Graphic Communications
Montrial (Quibec) Canada T. (514) 389-5061 F. (514) 389-5840
email@hidden