How about BOTH? 1) User places nubs on convenient "rectangle" in picture 2) QC Plugin performs correction on THE WHOLE IMAGE. (QC also auto-crops the image so there's no transparent area on any edge -- done to minimize croppage.) 3) QC Plugin SELECTS the orginal, now orthogonal, rectangle. 4) User has option to now CROP to the selected rectangle. As with any rectangular selection. In other words, I agree with MJW.