IMO, it should be objdetect instead. Similar to groupRectangles() API.

(but need to resolve dependency issue).

Originally I wanted to move all NMS stuff to the core module to be close with Rect and RotatedRect, but turned out NMS for RotatedRect uses rotatedRectangleIntersection and contourArea to calculate IOU which are in imgproc.

It seems impossible to move NMS to objdetect because then dnn would depend on it and we already have inverse dependency (objdetect on_dnn_).

I think, ideally all geometry-related classes and algorithms should be moved to the core or a separate module - large part of core/types.hpp, operations with rectangles and contours (but not findContours) - all of this does not operate with pixels and does not depend on Mat.

IMO, it should be objdetect instead.

I agree with this. core module makes sense as well. imgproc is more like a image processing module but NMSBoxes or NMSBoxesBatched is operation on boxes.

If the API move is being proceeding still, we can leave the legacy API calling the new one from other module, leave a warning for API deprecation and remove the legacy one completely in some point.

Discussed on OpenCV core team meating. Found alternative solution. Closed.

@asmorkalov, Once an alternative solution will be published, may I ask to refer it here? Just to be on touch. Thanks in advance!