What is the role of bbox_inside_weights in Faster-rcnn code

This blog post mainly synthesizes the answers of the two previous answerers, here only for the purpose of learning records:

Reference connection: https://www.zhihu.com/question/65587875

 

There are two variables in the Faster R-CNN code that are difficult to understand: bbox_inside_weights and bbox_outside_weights. After referring to some answers, understand a little bit, and record briefly here.

1. bbox_inside_weights

Used to set the weight of positive sample regression loss, the default is 1.

 

You can see the second half of the bounding box regression, where Pi * refers to regression only for the foreground (fg), and bbox_inside_weights refers to this.

In the code block, initially inside_weights is an all-zero matrix, and then write (1.0, 1.0, 1.0, 1.0) where label = 1

 

2. bbox_outside_weights

The bbox_outside_weights should be Nreg, which acts as a denominator.