Coagula is an image synthesizer, both an image editor and a sound generator from an image.

Note: It seems that the software hasn't been updated for several years - the version linked to this page is the latest to exist.

What are the key features of Coagula?

It can generate rich and complex sounds.
It has all the valuable tools to draw and create images.
It includes lots of specific tools that cannot be found in other image editors.

NB: However, it lacks many things that should be included in any image editor. It shows that it is meant for a particular thing between the world of music and image. Here, the color intensity and contrast are used to indicate sound amplification. There are many ways to handle the software, and time is needed to master it.