I'm looking for a good filter or other effect idea that I would make for a school project. Anyone have any ideas?
You might consider creating a "color cube" plugin that would display an image's distribution of colors within a 3-D cube.
Here is an example showing the color distribution of da Vinci's Mona Lisa:http://barn.kerosenecow.net/mgoblin_media/media_entries/105/monolisa-colorcube.jpg
I wrote a simple Script-fu (see link below) to generate the above image, but a proper plugin would offer a preview window that could be rotated to view the cube from different angles.
depends what you mean by school. A bandpass filter would be interesting.