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Fractal Software => Programming => Topic started by: bkercso on July 17, 2015, 01:49:51 AM




Title: Parametric color mapping techniques
Post by: bkercso on July 17, 2015, 01:49:51 AM
Hi,

I developed a new color mapping function that is better (ie. results nicer images) than logarithmic one for bifurcation fractals and maybe for other type of fractals. I call it "hyperbolic" coloring. This has a parameter which I call "reveal".

The function is (where x is the count density of pixel, min and max are min. and max. of xs):
Code:
MAXX:=max;
min:=abs(1/(min/MAXX+reveal)-1/reveal);
max:=abs(1/(max/MAXX+reveal)-1/reveal);
x:=abs(1/(x/MAXX+reveal)-1/reveal);

color[0..255]=(x-min)/(max-min)*255;

And my logarithmic coloring function for x>=0 values is:
Code:
min:=ln(min+1.1);
max:=ln(max+1.1);
x:=ln(x+1.1);

color[0..255]=(x-min)/(max-min)*255;

Here is a comparison graph of this hyperbolic and logarithmic coloring. What you can see is hyperbolic method reveals better the differences in lower range of xs. If reveal is lower lower range of xs will be revealed. reveal=0.001..0.1 is recommended, but it depends on max.
(http://nocache-nocookies.digitalgott.com/gallery/18/4917_17_07_15_1_28_53.png)


Hope you will enjoy it; and please write here other useful formulas which you find (or put this post to the proper topic...)! ;)


Regards,
Bert


Title: Re: Parametric color mapping techniques
Post by: bkercso on July 17, 2015, 02:03:39 AM
Feel the difference!!

(http://s11.postimg.org/7v2aq5vsz/Coloring_Comparison.png) (http://postimage.org/)


Title: Re: Parametric color mapping techniques
Post by: bkercso on July 17, 2015, 02:20:35 AM
(http://s21.postimg.org/fueluy6ev/Coloring_Comparison2.png) (http://postimage.org/)