Bob Hughes wrote:
> 
> I converted your image to grayscale using Micrografx Picture Publisher
> and it really shows the changes from one to the other. The "red shadow"
> I mentioned before, I think this is actually a reddish hemisphere
> instead, it obviously loses the dark to light shading it had in the
> color image in your example. When the whole thing is converted via P.P.
> it remains shaded properly as expected. And that color image with the
> all-blue box at the spheres equator is a puzzle to me. It has no
> shading, then in the macro-converted grayscale it does?! Strange. That's
> what I was pointing out before.

Yes, I know it's not perfect, but I think it's fairly good, esp. if there is no
original.. I don't have the time to tweak it here, you could if you like, but
noone is forcing you. :-)
(see below for the shading question.)

> So you think there are other conversion formulas possible? I see you
> used the one in the POV-Ray DOC under hf_gray_16 output. Wonder why this
> wouldn't already be right?

I think it's because there is no gamma-correction done on that. I think the
gamma is based on the colour of the image, no?  and that is the difference.
 

-- 
//Spider 
( spi### [at] bahnhofse ) [ http://www.bahnhof.se/~spider/ ]
#declare life = rand(seed(42))*sqrt(-1);

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