RandomJ: Exponential

General Description

This plugin enables one to contaminate images with random numbers generated using an exponential random variable.

Dialog Description

Lambda. The parameter of the probability density function of the exponential random variable:

Exponential PDF

The parameter must be larger than zero.

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

Implementation Details

The algorithm is based on taking the natural logarithm of uniform random numbers, the latter of which are obtained from the Uniform plugin. 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 run of this plugin, provided there is a time interval of at least one millisecond between the runs.

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.