For many tools it makes sense that they are applied on the whole image. However, for a select few (automation) tools I can think of (at least) one use case, where it would be really beneficial if they were only applied to the active crop area. There are already tools that do, like the Vignette filter. The Histogram also only shows the values from the crop. So it’s not something completely new.
I know this has been discussed in the past (see e.g. #709), but I would like broaden the discussion a bit. The use-case I refer to (and for which it would also have personal benefit) is editing of scanned negatives or slides (example here). I usually need to rotate and crop portions off from the picture to get rid of the dark slide frame. However, when using for example the Auto Levels, or the new Auto-Matched Tone Curve, or the White Balance tool, or the automatic chrominance Noise Reduction, it takes into account the unwanted black border. This leaves me with sub-optimal starting conditions for further fine-tuning and more work. The mentioned tools usually work wonders for regular pictures.
I believe my argument comes from the impression that whatever you crop, you don’t want to use. Then it simply no longer makes sense to consider the image data you threw out, and go for an apply-after-crop possibility for these tools. But I might be wrong, or I might be short-sighted, so please change my view! Do you think it would be worthwhile to implement apply-after-crop possibilities? I love to hear arguments from both sides. Maybe I missed an important other use-case, or another tool for which it would be beneficial to work post-crop. So please, share your thoughts