Note that every pixel is one brick. If you do a 1280x1024 image, that's 1,310,720 bricks. Not only that, you're reading the data of all that whilst loading. Of course it'd crash you.
It's why this is discouraged. No one knows how to do it and it took the fun out of actually remaking images by hand. Luckily, most versions of it fail to match colors correctly.