Connect the motor using motor driver.
Write and run the code for the stepper motor. Able to control the motor (speed, no of steps)
Here is the simple code to test the motor :
https://makeyfiles.s3.amazonaws.com/3489/sketch_may30a.ino
Also this tutorial can help :
https://www.youtube.com/watch?v=LtJM-8rokGg

Read about pixels ad types of images - https://www.youtube.com/watch?v=0-WV7LfoX7k
Write a code of image thresholding - https://www.youtube.com/watch?v=0-WV7LfoX7k