I created images that fit perfectly into the visible area of a split but the image was always shifted up or down due to the 48 pixels of the taskbar and correcting with +48 or -48 of the vertical pixels setting didn't seem to work as I expected.

What finally worked was simply setting the sizing to 'Tile', which seems to align the image to the top of the slice (and I assume also to the left).

The alignment of sizing 'Center' seems obviously but it's unclear if the horizontal/vertical adjustments occur after centering or before.

For the 'Best fit' sizing, is the image alignment also center?

Wouldn't it be nice we can directly pick the image alignment (8 directions or center)?

My use case is that I have several images that are exactly of the same scene but differ in time-of-day. So I wanted each image to span my splits but then have each split randomly show a different time of day of that part of the image. So I manually split my images to fit each split and needed the image to be shown exactly unaltered so all the images would align perfectly. It would be nice if DF could do something like this by itself!