[Radiance-general] colorpict and materials

[Greg Ward]

Hi Lars,

I guess no one really understood your question.  I'm away on travel, 
with spotty access to e-mail, so I missed this one.  I still think I'm 
missing the question.  You can use the pfilt command to adjust the 
overall image brightness used by brightpict or colorpict -- is this 
what you're asking?

-Greg

> From: "Lars O. Grobe" <grobe at gmx.net>
> Date: June 24, 2004 11:06:45 AM GMT+01:00
>
> Hi!
>
> I have a question regarding the proper use of colorpicts.
>
> I have "calibrated" pics of materials (using macbethcal) that I used 
> to get the rgb-values for material definitions. These samples have 
> typically dimensions of about 30 x 20 cm (similar to the Macbeth 
> colorchecker). I rendered using the materials colors obtained from 
> these samples.
>
> Now I want to map pictures onto the surfaces. I still want to use the 
> color as obtained from the sample. But the mapped picture is usually 
> much larger than the sample. So I would need a way to bring the 
> average color of the picture to the (average) color of the calibrated 
> sample. Is there a way to do that with Radiance's tools? I could use 
> these mappings on a clear white (.9 .9 .9) surface than, right?
>
> Is there a way to use the pic only as variation of the color? E.g. 
> converting from radiance pic to a file that could be used by 
> brightdata? I could use the color from the calibrated (small) sample 
> than, and the big pattern only to map some structure.
>
> The way I used so far: applying normpat to a grayscale pattern, and 
> mapping that onto the surface which has the color measured from the 
> sample. Similar to using brightdata, and not able to reflect the color 
> variation.
>
> Thanks, CU Lars.
> --
> Lars O. Grobe, grobe at gmx.net, ++90-212-2458330
>
> Kardesler Apartment, Turnacibasi Sokak 28
> Galatasaray - Beyoglu, 34433 Istanbul