Loading, comparing and saving images?

Dear madam/sir

I was wondering if it was possible for a .NET website to:


1) load an image into it's page(lets say www.google.be/img.php?hash=f5y2g6re5ef5r2v5e5vv8e5v5e58ver8f),

2)Compare that image to the images you already have (pixel wise, I need a 100% match),

3) Save the loaded image if you don't have it yet?

All help appreciated!
Thank you for your time and dedication.

Andrew
...