How are image processing and computer vision related to artificial intelligence.?
The answer is simple.

Assume you are making a robot for interacting with other people. The first thing that it needs is to recognize people who it sees.

Another application is in self-driving cars. If the car is not able to see the road and read the signs or break when it sees a dangerous obstacle ahead, how could it drive in a safe way?

There are a lot of smart agents who need to see an recognize a scene or a person and many other applications; this is where computer vision and image processing come handy. One of the best techniques that is used in Computer Vision is machine learning which is one of the cutting-edge methods in AI.