Question

I have to make an application that recognizes inside an black and white image a piece of tetris given by the user. I read the image to analyze into an array.

How can I do something like this using C?

Answer 1

Assuming that you already loaded the images into arrays, what about using regular expressions?
You don’t need exact shape matching but approximately, so why not give it a try!

Edit: I downloaded your doc file. You must identify a random pattern among random figures on a 2D array so regex isn’t suitable for this problem, lets say that’s the bad news. The good news is that your homework is not exactly image processing, and it’s much easier.

It’s your homework so I won’t create the code for you but I can give you directions.

1. You need a routine that can create a new piece from the original pattern/piece rotated. (note: with piece I mean the 4×4 square – all the cells of it)
2. You need a routine that checks if a piece matches an area from the 2D image at position x,y – the matching area would have corners (x-2, y-2, x+1, y+1).
3. You search by checking every image position (x,y) for a match.

Since you must use parallelism you can create 4 threads and assign to each thread a different rotation to search.