Hi Jonathan, I don't think the resampling in PC Sharpening has any different effect than if you are simply co-registering two images (which is why you resample in PC sharpening). The same reasons for using a particular resampling method applies - you have warped an image to match another and the grid is different so you have to choose a method to re-assign pixel values. Nearest neighbor will retain the original values so it is best for spectral integrity, but since you are sharpening the image and thus affecting the spectral integrity anyway, it isn't as important. Bilinear and CC will generally give a smoother appearance along borders. -mm