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thangvubk / SoftGroup

[CVPR 2022 Oral] SoftGroup for Instance Segmentation on 3D Point Clouds
MIT License
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Question about NMS #61

Closed mbaicad closed 2 years ago

mbaicad commented 2 years ago

Thanks for you great work.

Reading your paper and comparing to PointGroup and HAIS, I wondered why SoftGroup does not require some sort of non-maximum suppression (NMS). AFAIK PointGroup does require NMS, while HAIS does not, since no point will be grouped to multiple cluster proposals. However with SoftGroup, my understanding is that a point can be in multiple cluster proposals. So how come no NMS is required?

thangvubk commented 2 years ago

Even though a point can be in multiple cluster proposals, its score in the corresponding classes should be high enough. Moreover, the overlap ratio is rarely higher than NMS threshold (e.g., IoU of 0.5) so NMS is not mandatory.