Algorithm 1: estimation process
Input: Anchor Set: ; Image Batch; Total number of anchors: ; The number of classes ; FPN network ; RPN network; ROIHead network.
Output: Class prior;
1 for Image do
2 Compute FPN features
3 Compute the probabilities predicted by RPN
4 # Filter proposals with a fixed threshold (0.05 in detectron2) for the probabilities.
5 Select proposals
6 # Compute the probabilities and bounding boxes predicted by ROIHead.
7 ;
8 # Filter the predicted boxes based on a configured confidence threshold .
9
10 Determine the index of positive anchors with and according to Equation (12).
11 Collect the set of as
12 Compute the class prior of one image
13
14 end
Return