You can probably write a small program to "solve the puzzle". Start with one piece and check for the piece that has the same adjacent pixels. It should work for most pieces, except where there is a borderline of nonmatching pixels. It would also require manual placement of things like the number label.
Edit
orry, i didn't realize that pieces weren't aligned. The problem is a bit more complicated now, but I'm sure there's a way to automate the task.
Edit
orry, i didn't realize that pieces weren't aligned. The problem is a bit more complicated now, but I'm sure there's a way to automate the task.