Original image rendered from the game and cropped by me:
Converted to .ldimg file, and rendered (using composite NTSC) by Raspberry Pi:
Now let's examine one place:
Here is the original. Notice the border on the right side is dark green with a grey patch of a zombie's shirt.
Here is the pi version. It's a little hard to tell, but the right side is completely black and the grey patch from the zombie's shirt is nowhere to be seen.
The pi does not shrink a source 720x480 image but instead overwrites the left and right borders with black. This means that discs that are captured in 720x480 should be re-encoded "as is" without getting rid of the black borders.