nice code177, great work!
just a question: does splitting a jpeg image reencode it? is there a loss of quality? (even in the case it is very small, just to know it, sometimes I'm a bit perfectionist )

so far I did all the working and splitting in png, and encoded to jpg only at the end (not with mspaint!). splitting the png was done in mspaint, with an intelligent use of "flip horizontal" and "resize to 800/1600"
I know I'm a noob with graphics, but I had my method