Can we use Python to write codes for image processing?

Answer 1

Images are files except instead of reading a line at a time you'll have to read bytes at a time. The processing that you do after that will depend on the encoding of the image that was used.

Answer 2

have a look at SimpleCV

Answer 3

yes you can if you are implementing your own algorithms then you can simply parse them in array and and if you are just looking for colours adjustment, edge detection I strongly suggest you to use openCV