HelpImage Searcher

Hey Guys,
I want to write a program that searches a screenshot or a other image for a little patternin it and returns the coordinatesof the pattern.
Here is a example:
I want to find this "pattern"
-attached as pattern.png-
in this big image
-attached as screenshot.png-


and get the coordinatesof of the pattern.

Thank you

Oh my, not a very easy task. Nice little project though. I suggest reading about images and how they store their bytes. I think it depends per extension. Then what you do is try to find if there are the same sequel of bytes stored on the other image, if the sequel is found see where this sequel starts exactly in the entire storage and you probably got your coordinates.