In article <391026EB.BFD05720@aetec.ee>, Vahur Krouverk 
<vah### [at] aetecee> wrote:

> I didn't knew about them either, but with help of CG Bible (by Damn,
> Fool et al;-) and colorspace FAQ from POV-Ray CD it appeared to be not
> too hard to implement.

Is this colorspace FAQ available online?


> For color space conversion filter and transmit have no value, so
> probably those functions could use vector type as well.

Well, they shouldn't be affected by the conversion, but if someone feeds 
a color containing filter or transmit through rgb2hsl() and then through 
hsl2rgb(), the result will be the same color but stripped of the filter 
and transmit values. Not an extremely serious problem, most of the time 
you won't notice it, but it is a problem.


> This means, that conversion vector<=>colour should be available (is 
> it?).

Colors are 5-dimensional vectors. If used as vectors, filter and 
transmit are ignored. Vectors can be used as colors, filter and transmit 
are set to 0 in this case.


> > The post_process versions wouldn't require any parameters.
> I'm not sure I that understand this, (I haven't observed post-processing
> evolvement very closely), care to explain?

I mean with the functions, you feed it a color and get a color in 
return. With the post_process filter, you just specify a conversion 
filter-it takes the image as input and replaces it with the output. You 
could then use add, subtract, multiply, etc to manipulate each "channel" 
and convert back to rgb.

-- 
Christopher James Huff - Personal e-mail: chr### [at] yahoocom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://chrishuff.dhs.org/
TAG Web page: http://tag.povray.org/

Post a reply to this message