Setup: Unzip the zip files in third_party/ so that you have the directories
third_party/Imaging-1.1.7/ and third_party/zlib/.

Usage: python hitbox_expander.py <path_to_file.dmi or png>

This tool expands the hitbox of the given image by 1 pixel.
Works by changing some of the fully-transparent pixels to alpha=1 black pixels.
Naked human eye usually cannot notice the difference.

No space carps or corgis have been used or injured in the production of this tool.