These plugins apply user-specified formulas to each pixel in an image. They can be used to alter existing images, or to create fully synthetic new images.
Expression does this by interpreting the formula for each pixel; this makes it somewhat slow for complex formulas. ExpressionNT compiles the formula as a Java class and executes it; this makes for much faster execution. It also has extra functionality to generate fractal images, and supports the HLS and HSV color models. In general, ExpressionNT should be used, simply because it is so much faster.
The plugins can be found at: http://www.ulfdittmer.com/imagej/expression.html
by Ulf Dittmer — last modified on April 2 2008