<Jer### [at] enstfr> wrote:

> > "all" makes more sense than "grey".
> 	I think it depends on what the spline does exactly: is it the same as:
> rgb SPLINE, SPLINE, SPLINE
> 	Or does it only change the brightness?

It uses the same spline to adjust each channel. The current value of the 
channel is taken as the "t" value of the spline, and the result of the 
spline is used as the new value for the channel.


> A good thing to add too: spline-based manipulations on hue and 
> saturation...

Not as a special feature of the spline patch...just use a rgb_to_hsl 
filter, then use the ordinary curves filter to adjust hue or saturation, 
then use hsl_to_rgb to get the corrected image back. More flexible, less 
complicated, and you can combine it with other things to get special 
effects. And I *am* planning to write these conversion filters...as soon 
as I figure out the math. I've found lots of information about 
converting between color spaces, but little or nothing about the actual 
equations used to convert between rgb and hsl. That, or I'm just not 
recognizing it when I see it...

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

Post a reply to this message