Re: [Openexr-devel] Embedding ICC profiles in OpenEXR

[Geraldine Joffre]

On Tue, 22 Nov 2005 09:38:48 +0100 (CET), Kai-Uwe Behrmann wrote
> What CMMs are known, that handle HDR content properly, including 
> support of:
> o floating point precission, 
> o a value range greater than one and possibly lower than zero. 
> ?
If you are using the CMM for display purposes, 16-bit precision is far enough 
for standard 
monitors. 
 
> Without such a CMM, ICC profiles could only be used for displaying 
I agree, but many applications just need the CMM for displaying the HDR image.

> or could easily degrade the content by integer math manipulations.
Yes if you want to change the color space of the HDR image. Normally, you only 
need to change 
the color space for display or printing, and this will be done on the Low 
Dynamic Range version 
of the HDRI (expect for users who have an HDR display at their disposal, but 
this is a very small 
minority for the moment).

> Wich CMM is used in Photomatix?
Own CMM for the currrent version in development, though we are considering 
replacing it by 
LCMS. Photomatix is not an HDR image editor, it only needs the functions of a 
CMM for display 
and for embedding a profile in the tone mapped LDR images. I believe many 
applications 
targeted at photographers will have the same requirements once they get into 
HDR, which is 
why I think it would be great if OpenEXR files could embed ICC profiles.