Fixing Extra Drawn Row

Created by: Lacaranian

The ImageRoi was drawing an extra row due to how it calculated the endpoint for its row-by-row approach. Fix involved a reduction by 1 of the rows considered.

Of note, ImageRois with no height and a width smaller than the total images width could result in a negative end, which in turn would cause nothing to be drawn; this isn't strictly an issue though, as no height implies nothing drawn.