Hello, I'm making a project for my university which requires me to make use of the Arduino (Uno or Mega) to capture a picture of a car, and use an OCR algorithm to process and print it as text and then save it to a database.
I'm relatively new to Arduino but I've learned a lot in the past few month, but I still don't know how to do this implementation. 
How would I write a program that would make arduino ask the camera to take a picture and then save that picture in a specific folder.
Thanks!
ask the camera
Your use of a definite article there confuses me.
How would I write a program that would make arduino ask the camera to take a picture and then save that picture in a specific folder.
Break this down into separate tasks and get each one working before putting them all together. The first would be to get an Arduino-compatible camera and figure out how to use it.
You need something that can run computer vision code, that's massively
beyond an Uno's capabilities, it only has 2k RAM