
Earlier today, I came across an odd program called Audiopaint, now in its iteration for 2007. Audiopaint is a spectral synthesizer, and for those of you who don't know what that is, a spectral synthesizer takes an digital image and translates it into sound.
It works a little something like this: each pixel in the digital picture has two data values (the coordinates of its position in the digital image). The Y value of the coordinate determines what pitch the pixel will produce, and the X value correlates to when the note is played (the X axis is a time line, similar to they way a sequencer works, it scrolls from left to right playing a pixel's pitch as it is hit). Furthermore, a spectral synthesizer uses additive synthesis as many notes are played simultaneously by individual oscillators. This is just a brief look at how a spectral synth works, the applet javoice has a very detailed description of how a spectral synth works and even lets you translate sound into an image.
Anyways, Audiopaint 2007 is a brilliant synth that responds not only to pixel coordinates but also color data (by default, level of red controlls how loud the left channel is, and green the right, this seems a little backwards, I always associate red with right...), making it ideal for all types of images. It accepts a variety of filetypes, but its coolest feature is the fact that it uses granular synthesis (sample based oscillators) to create the sound based on the image. This means that you can feed the program a snippet of your voice, and see how it is then used to generate a texture based on the image you provide. There are a few other audio paramaters you can tweak, such as how fast the X axis timeline is scrolled across (determined by user defined length of sample output). This means you can create a long, rich texture of sound without having to timewarp the sample.
The Audiopaint 2007 page is right here. The page provides a link to a database of images taken by the hubble telescope for you to play around with which is very cool. I think this is a very useful tool for any sound designer that can't be passed up.
Here is an example of something I've made with the program. I took this image:

and translated it into this sound with Audiopaint: click here for mp3.