Problem Set Five.

Genetic Image Filtering with Sol II

In this assignment I refined the genetic image filter breeding system I wrote for problem set four and applied it to the problem of breeding a specific kind of filter, rather than simply any filter that produced cool results.

This is a much harder problem, because one of the constraints I set myself is that I would not tinker directly with the filter DNA; I would rely on selective breeding only, and not genetic engineering. Further, I wanted to see if I could start from the initial filters I had generated from the previous assignment, rather than writing a new batch of custom filters to begin from.

The images below document a single sequence of filter breeding, with interesting results at each step of the way shown separately along with their genetic code.

The initial filters.

Source images.

The first interesting results

The second generation.

The third generation.

The fourth generation.

The fourth generation.

The last generation.

Description

The images you see here are the result of breeding image filters using genetic programming techniques. This was a directed breeding program - the goal was to produce a filter for the target image which would emphasize the background and de-emphasize the foreground (problem set five). This is a difficult task, because the chosen image lacks simple differentiating features (like contrast, hue, etc.) which distinguish the background from the foreground. When the Genetic Filter applet starts, the user is given a selection of seven initial filters as applied to a source image. The user may choose another source image from a list, edit the genetic code of a particular filter, or select two filters to be "parents" of a new generation of child filters.

When two parents are selected and the "combine" button is pressed, the applet generates seven new image filters which are the genetic descendents of the two parent filters. These child filters are a combination of the genetic code for the parent filters with possible additional code introduced by mutation. The new filters are then applied to the selected source image and the user is shown the results. The cycle of filter selection, recombination, and display is repeated as many times as desired. In this way, the aesthetic sense of the user acts as the fitness function for the genetic evolution of the system. Once an image is created which the user likes, a larger version may be rendered in a new window and captured from the screen, as these example images were.

The filter results shown here were the results of four generations of filter evolution.

last updated Thu Oct 15 12:23:22 EDT 1998
rich@media.mit.edu