Need help: camera scanning - midi, motors speed

I have a massive art thesis in the works, and my intent is to create a camera or scanner on a grid that will scan a painting, and in realtime translate the output data into midi notes and also into motor speeds to control dc motors that will play piano wires. I am a total noob - I have done a program and controller to do the motors, but the input on off was very similar to a flashing led example, and that is about my extent of knowledge. Any ideas about hardware, what software to interface with, programming possibilites, or any other advice would be very welcomed. I have access to a few controllers to do this, but would like to keep it simple, and the cost fairly low.
Also, I apologize if this is in the wrong area. I searched for similar topics. First post, So please let me know what I could do better, or what information I'm missing. Like I said, I'm in a little over my head, and really don't even quite know where to start, or what the limitations will be.

This is the best I can describe it now:

If I have a cmyk scanner or digital camera image,
there are 8 notes in an octave, so levels of each signal can be split to associate with a note.
say, cyan, levels (I don't know what the actual output would be) range, perhaps, between 1 and 1000. 1 - 500 will be A's, 501 - 1000 will be B's. The level will determine two factors in a grid - both the octave (A1, A2) and the intensity. I may be limited simply to notes, but I can create humanizing controls over the midi signal, perhaps from another input source that would be velocity, or have the signal levels serve to control both aspects. Then, Yellow would be another 2 notes.

For the motor controller, hopefully each signal is an individual wire or can be split, so that Magenta will be on pin 3, Cyan on pin 1 of input. From there, the signals will again be split to control motors - if less than #, control motor 1 speed, with speed controlled by signal level, if more than #, control motor 2 speed, and so on. With a single controller, you can either control 4 motors bidirectionally, or 8 single direction, as long as they share a common ground. Each motor will have its own string to play with zip ties or brushed wheels, so a single direction is all that is needed. The strings will be tuned to specific notes, but what length the note is played for, or when it is played, is left to chance.

Thanks for any input!

Thanks for commenting. I would like to set up a track for motors to travel over, doing an x/y grid scan of a physical painting, with the performance aspect part of the piece. I have implemented motors for strings in a previous sculptural/sound piece, but the code was entered directly to the arduino, with no input sources. It's somewhat of a 3 stage project, with a painting, a plotter or similar thing to go over the image, and then a sculpture with strings and motors that play them. I'm good on the last part, as far as making motors play strings. I just don't know which way to go. RGB would work just as well - I just need to be able to assign values to 8 notes of midi and 8 motors, as I tried to describe. Hopefully that adds clarification. Thanks for the prompt reply!