Getting RGB values from camera
No. The Arduino (or not the "normal" Arduinos) doesn't have enough memory to decompress JPEG.

I made a JPEG decompressor for chipKIT boards the other day, and it uses the absolute bare minimum memory possible, and still comes it at close to 128kB. Far more than any "normal" Arduino board.

You can possibly do it with one of these new-fangled Linux-based Intel boards that are being sold as Arduino these days, but they are not your normal run-of-the-mill Microcontroller but closer to a Raspberry Pi.

Speaking of which, the Raspberry Pi is probably a much better choice than any Arduino board for the kind of thing you are trying to do.