problem about NMS algroithm

[xiaohu2015]

I think we shpuld do NMS on the boxes for each class. But using tf.image.non_max_suppression means you treat all classes equally. It may be bad.

[tgandor]

I think it's a trade-off. Plus side: different objects overlapping or 'entangled' can be let through. Minus side: false positives for weaker classes on the same object (like in YOLO3 article addendum, in the discussion about COCO AP metric).