Some experiments point to overflowing 16-bit integers rather than memory
resource issues:-
1. My script can load a 16383 x 1321 image but gets "Out of memory" on a a
16384 x 1321 image.
2. A workaround to load the image in PIL and transfer it to pygame as a
string works as long as the width is less than 21846 and the height is less
than 32768, otherwise the image is totally garbled. (Note that 21845 x 3 =
0xFFFF.)