mmdet.models.necks.hrfpn 源代码

import torch
import torch.nn as nn
import torch.nn.functional as F
from mmcv.cnn import ConvModule
from mmcv.runner import BaseModule
from torch.utils.checkpoint import checkpoint

from ..builder import NECKS

[文档]@NECKS.register_module() class HRFPN(BaseModule): """HRFPN (High Resolution Feature Pyramids) paper: `High-Resolution Representations for Labeling Pixels and Regions <>`_. Args: in_channels (list): number of channels for each branch. out_channels (int): output channels of feature pyramids. num_outs (int): number of output stages. pooling_type (str): pooling for generating feature pyramids from {MAX, AVG}. conv_cfg (dict): dictionary to construct and config conv layer. norm_cfg (dict): dictionary to construct and config norm layer. with_cp (bool): Use checkpoint or not. Using checkpoint will save some memory while slowing down the training speed. stride (int): stride of 3x3 convolutional layers init_cfg (dict or list[dict], optional): Initialization config dict. """ def __init__(self, in_channels, out_channels, num_outs=5, pooling_type='AVG', conv_cfg=None, norm_cfg=None, with_cp=False, stride=1, init_cfg=dict(type='Caffe2Xavier', layer='Conv2d')): super(HRFPN, self).__init__(init_cfg) assert isinstance(in_channels, list) self.in_channels = in_channels self.out_channels = out_channels self.num_ins = len(in_channels) self.num_outs = num_outs self.with_cp = with_cp self.conv_cfg = conv_cfg self.norm_cfg = norm_cfg self.reduction_conv = ConvModule( sum(in_channels), out_channels, kernel_size=1, conv_cfg=self.conv_cfg, act_cfg=None) self.fpn_convs = nn.ModuleList() for i in range(self.num_outs): self.fpn_convs.append( ConvModule( out_channels, out_channels, kernel_size=3, padding=1, stride=stride, conv_cfg=self.conv_cfg, act_cfg=None)) if pooling_type == 'MAX': self.pooling = F.max_pool2d else: self.pooling = F.avg_pool2d
[文档] def forward(self, inputs): """Forward function.""" assert len(inputs) == self.num_ins outs = [inputs[0]] for i in range(1, self.num_ins): outs.append( F.interpolate(inputs[i], scale_factor=2**i, mode='bilinear')) out =, dim=1) if out.requires_grad and self.with_cp: out = checkpoint(self.reduction_conv, out) else: out = self.reduction_conv(out) outs = [out] for i in range(1, self.num_outs): outs.append(self.pooling(out, kernel_size=2**i, stride=2**i)) outputs = [] for i in range(self.num_outs): if outs[i].requires_grad and self.with_cp: tmp_out = checkpoint(self.fpn_convs[i], outs[i]) else: tmp_out = self.fpn_convs[i](outs[i]) outputs.append(tmp_out) return tuple(outputs)