Resize check

[rcastill]

I would like to be able to resize to a target resolution and don't need to check if the target resolution is already the image's resolution.

My specific use case for this functionality is that I found this to be a huge bottleneck in a real time object detection application. Resize itself took some time, so I pre-processed the image so it came already resized from another thread. Performance improved, but profiling still showed that the guts of resize where being called (vertical/horizontal_sample). Checking if it was already resized, hugely improved my application's performance.

This is more generally applicable to people that could face the same problem. Maybe it's a better default to check first.

Draft

It's a simple check using GenericImageView::dimensions().

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I also understand it may be a design decision to leave this check to the user. But I wanted to raise the question.

[fintelia]

This seems like a reasonable feature addition to me. The cost of checking should be a tiny fraction of the total time spent resizing an image