File:Mandelbrot inside (64 iters B&W).gif
Mandelbrot set, a fractal. Here it's inside is colourised from a special method named "palette walk".
In this example the function uses 64 iterations and a palette of 128 colours. It starts from palette index = 64. Then in every iteration it tests for x * y < 0, if true then it decreases the palette index by 1, else it will be incremented by 1.
The method can also be used to colourise the outside (the "aura" of the fractal). If one uses two palettes then it can be combined with the normal colour-mapping method, (the count of iterations used as palette index). A example of the combination method is the image Julia set (C = 0.285, 0.01) II.jpg.
See also: