maskrcnn_benchmark学习笔记——modeling\rpn\anchor_generator.py

基于一组图像尺寸和特征图层的具体数值设置（如 anchor\_sizes 为(32, 64, 128, 256, 512)），计算出相应的锚点集合。具体来说，
基于这一组图像尺寸和特征图层，
anchor\_sizes 为(32, 64, 128, 256, 512),
aspect\_ratios 为(0.5\texttt{_},\texttt{}1.\texttt{_},\texttt{}2.\texttt{~}),
anchor\_stride 为(4,\texttt{_}8,\texttt{}16,\texttt{_}32,\texttt{}64)，
即P\textsubscript{P}\textsubscript{#}_P\textsubscript{#}_P#，
straddle\_thresh 设为0

 # Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.

    
 import math
    
  
    
 import numpy as np
    
 import torch
    
 from torch import nn
    
  
    
 from maskrcnn_benchmark