Confused about the bbox_transform

[lucienne999]

Hi, I'm confusing the bbox_transform method in this file:

Detectron.pytorch/lib/utils/net.py

Line 15 in dcfab5f

def bbox_transform(deltas, weights):

As the method shows, it directly transform the bbox_delta (dx,dy,dw,dh) to pred_bbox (x1,y1,x2,y2) without the information of the ROIs. Obviously, it is impossible. Therefore, is there something I misunderstanding?