ScaleRatio introduces black border (NaNs) and unnecessary code duplication in ScaleRatio, ScaleKeepAspect and ScaleFixed #102
Description
Hey,
I have to switch from the old Augmentor.jl to this package and while converting my code I realized that ScaleRatio introduces a black border. Digging into the code, I saw that this was fixed for ScaleFixed and supposely fixed for ScaleKeepAspect.
I think this slipped through because all of these projections are implemented over and over again. I gave it a shot at unifying the codebase. This fixed the black border issue for ScaleRatio and ScaleKeepAspect.
In ScaleKeepAspect the issue remained sometimes because of the offset of 0.5 while ScaleFixed used an offset of 1.
I think unification additonally helps as, to my understanding, these 3 projections just provide different interfaces to the same scaling projection.
I will add a PR.