mkFractalSra

Name

mkFractalSra - make fractal brownian motion noise

Syntax

mkFractalSra [-sw] <output image> <D> [<xsize> [<ysize>]]

Description

Generates fractional brownian motion noise with fractal dimension D. The algorithm is known as "Successive Random Addition"

   output image - name of generated image
   D            - fractal dimension between 2. and 3.
   xsize        - xsize of synthesized image
                  (default 512)
   ysize        - ysize of synthesized image
                  (default xsize)

Switches:

   -mean        - mean pixel value for corners
                  (default 128.0)
   -cstd        - standard deviation for corners
                  (default 5.0)
   -std         - init. st. dev. for other pixels
                  (default 25.0)

Note that mean far from 128 combined with large standard deviations will give a lot of over/under-flows, and a very poor result. cstdev should be small to avoid "tilting" the whole image.

Author

Håvard Iversen, BLAB, Ifi, UiO

Modifyed by

Tor Lønnestad, BLAB, Ifi, UiO

Reference

Fournier, A., Fussel, D., and Carpenter, L.: "Computer rendering of stochastic models", Commun. ACM 25, 6 (June 1982), 372-382.

Example

 mkFractalSra -mean 100.0 fractal.img 2.5 200 400

Id

$Id: mkFractalSra.c,v 1.29 1997/03/07 12:51:50 svein Exp $