RandomJ: Gamma


General Description

This plugin enables you to contaminate images with random numbers generated using a gamma random variable.

Gamma Dialog

Description of Dialog Components

Order. The order parameter of the probability density function of the gamma random variable:

Gamma PDF

where "alpha" is the order. In this case, the order must be an integer larger than zero.

Insertion. The random numbers can be inserted into the image either additively or multiplicatively.


Implementation Details

The generator is based on the algorithm given by Press et al. [1] and uses the Uniform plugin as a source of uniform random numbers. Since the uniform number generator is initialized with a seed derived from the system's current time in milliseconds, the sequence of random numbers will be different for each application of this plugin.


References

[1] W. H. Press, S. A. Teukolsky, W. T. Vetterling, B. P. Flannery. Numerical Recipes in C: The Art of Scientific Computing. 2nd ed., Cambridge University Press, Cambridge, 1992.
[2]A. Leon-Garcia. Probability and Random Processes for Electrical Engineering. Addison-Wesley Publishing Company, Reading, MA, 1989.
Copyright © 1996 - 2010 Erik Meijering