How to decrease and interpolate an image/video

edit

What do you mean by decrease? Size, resolution, quality? It may be weight or length?

I intend to do a project in my university, and the project is a POV Display: http://www.youtube.com/watch?v=QAGnpKz7zvY

I will do with a 32 LED RGB, and to send any image/video i will need to decrease the image, but decreasing it, probably it will get a bad quality to see and understand something, tha's why I need to interpolate too, so I think it need to decrease the size and interpolate to get some quality.

It's difficult to explain it, did you understand something that I said?