You can `jitter` the drawing. Draw the image four or eight times in black at the same coords except -1,0 then 1,0 then 0,-1 then 0,1 (add these to the normal coords).
If you want to do it 8 times, also draw it at -1,-1, -1,1, 1,-1 and 1,1 to cover the diagonals.
This will put a 1-pixel border around it. Then draw the regular image on top.
If you want to do it 8 times, also draw it at -1,-1, -1,1, 1,-1 and 1,1 to cover the diagonals.
This will put a 1-pixel border around it. Then draw the regular image on top.