[Radiance-general] Colordata question!

[Gregory J. Ward]

Hi Marija,

If you use the default "red" "green" and "blue" functions for rfunc,  
gfunc, and bfunc, you will get a bilinear interpolation by default.   
It may not look very nice, though, as bilinear interpolations tend to  
show "mach band" artifacts.  A simpler approach would be to convert  
your data into a low-resolution image then upsample it with pfilt.   
The conversion can be done using pvalue.

-Greg

> From: Marija Cvetkovic <cveleglg at bankerinter.net>
> Date: July 24, 2006 3:52:28 AM PDT
>
> Hi,
>
> I have rectangular surface with sensor points organized as a  
> regular 2D
> grid. The color of each sensor is defined based on sun exposure  
> data, I
> calculate separately (some kind of false-color). With this data I  
> can create an image with the surface and sensors on it, where color  
> of sensors define the distribution of sun exposure on the surface.
> Now, I want to make this representation continual (like the results of
> falsecolor program), so I must somehow interpolate the color data from
> the sensor points.
> My idea is to define the rectangular surface near the original one,  
> made
> of plastic with colordata pattern. Colordata takes next form:
> mod colordata id
> 7+n+
> rfunc gfunc bfunc rdatafile gdatafile bdatafile
> funcfile x1 x2  transform
> 0
> m A1 A2 .. Am
>
> rdatafile gdatafile bdatafile will be defined with my sensor colors.
>
> How should I define rfunc, gfunc, bfunc to enable bilinear or  
> bicubic interpolation of color?
>
> Related question:
> Are there any example of coloradata definition? I tried to find  
> them in the Book and in mail archives, but without success!
>
> Thanks,
> Marija