Detect too many instances on SOLOv2 demo.py

[Wong-denis]

I follow instruction on https://github.com/aim-uofa/AdelaiDet/blob/master/configs/SOLOv2/README.md#installation--quick-start
I only change the input image
And the number of instances on the output images is far more than the actual number of the images

Following is the result I get after entering
$ sudo python demo/demo.py --config-file configs/SOLOv2/R50_3x.yaml --input dog.jpg --opts MODEL.WEIGHTS SOLOv2_R50_3x.pth

Here is the output and original images of giraffes:
Also have the same problem

It seems that it didn't do the NMS. But I don't really know what happened.
Does anyone have any idea about how to fix this?