[Xr] API questions

Bill Spitzak spitzak at d2.com
Mon Jul 7 12:04:41 PDT 2003

On Monday 07 July 2003 01:07 am, David Forster wrote:

> Yes, hard to see how to get around it.  Floating point, however, is
> not necessary.  HP's e-sRGB color space defines values in the range
> -0.53 to 1.68, which is then mapped to a 10, 12 or 16-bit integer.
> This gamut is large enough for printers...The frame buffer could be in
> this format.

You should also look at ILM's "half" format, which is very likely to be a 
standard supported by shading hardware. It is basically a 16-bit IEEE float. 
Information and source is at http://www.openexr.com and it seems to be BSD 

Current hardware seems to be designed to assumme any 16-bit color values are 
stored as sRGB, there is no built-in conversion to the 8-bit display buffer 
other than multiplying by 255. We were able to do a linear->sRGB conversion 
by using a texture map and using the color to index it, but I don't think 
this was the intended use of the hardware design. So anyway this would 
indicate that any floating-point interface will probably need to be sRGB and 
not linear.

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