""" # --------------------------------------------------------------------------------- # -*- coding: utf-8 -*- ----------------------------------------------------------------------------------- # Copyright (c) Microsoft # Licensed under the MIT License. # Written by Bin Xiao (Bin.Xiao@microsoft.com) # Modified by Xingyi Zhou # Refer from: https://github.com/xingyizhou/CenterNet # Modifier: Nguyen Mau Dung (2020.08.09) # ------------------------------------------------------------------------------ """ from __future__ import absolute_import from __future__ import division from __future__ import print_function import os import torch import torch.nn as nn import torch.utils.model_zoo as model_zoo BN_MOMENTUM = 0.1 model_urls = { 'resnet18': 'https://download.pytorch.org/models/resnet18-5c106cde.pth', 'resnet34': 'https://download.pytorch.org/models/resnet34-333f7ec4.pth', 'resnet50': 'https://download.pytorch.org/models/resnet50-19c8e357.pth', 'resnet101': 'https://download.pytorch.org/models/resnet101-5d3b4d8f.pth', 'resnet152': 'https://download.pytorch.org/models/resnet152-b121ed2d.pth', } def conv3x3(in_planes, out_planes, stride=1): """3x3 convolution with padding""" return nn.Conv2d(in_planes, out_planes, kernel_size=3, stride=stride, padding=1, bias=False) class BasicBlock(nn.Module): expansion = 1 def __init__(self, inplanes, planes, stride=1, downsample=None): super(BasicBlock, self).__init__() self.conv1 = conv3x3(inplanes, planes, stride) self.bn1 = nn.BatchNorm2d(planes, momentum=BN_MOMENTUM) self.relu = nn.ReLU(inplace=True) self.conv2 = conv3x3(planes, planes) self.bn2 = nn.BatchNorm2d(planes, momentum=BN_MOMENTUM) self.downsample = downsample self.stride = stride def forward(self, x): residual = x out = self.conv1(x) out = self.bn1(out) out = self.relu(out) out = self.conv2(out) out = self.bn2(out) if self.downsample is not None: residual = self.downsample(x) out += residual out = self.relu(out) return out class Bottleneck(nn.Module): expansion = 4 def __init__(self, inplanes, planes, stride=1, downsample=None): super(Bottleneck, self).__init__() self.conv1 = nn.Conv2d(inplanes, planes, kernel_size=1, bias=False) self.bn1 = nn.BatchNorm2d(planes, momentum=BN_MOMENTUM) self.conv2 = nn.Conv2d(planes, planes, kernel_size=3, stride=stride, padding=1, bias=False) self.bn2 = nn.BatchNorm2d(planes, momentum=BN_MOMENTUM) self.conv3 = nn.Conv2d(planes, planes * self.expansion, kernel_size=1, bias=False) self.bn3 = nn.BatchNorm2d(planes * self.expansion, momentum=BN_MOMENTUM) self.relu = nn.ReLU(inplace=True) self.downsample = downsample self.stride = stride def forward(self, x): residual = x out = self.conv1(x) out = self.bn1(out) out = self.relu(out) out = self.conv2(out) out = self.bn2(out) out = self.relu(out) out = self.conv3(out) out = self.bn3(out) if self.downsample is not None: residual = self.downsample(x) out += residual out = self.relu(out) return out class PoseResNet(nn.Module): def __init__(self, block, layers, heads, head_conv, **kwargs): self.inplanes = 64 self.deconv_with_bias = False self.heads = heads super(PoseResNet, self).__init__() self.conv1 = nn.Conv2d(3, 64, kernel_size=7, stride=2, padding=3, bias=False) self.bn1 = nn.BatchNorm2d(64, momentum=BN_MOMENTUM) self.relu = nn.ReLU(inplace=True) self.maxpool = nn.MaxPool2d(kernel_size=3, stride=2, padding=1) self.layer1 = self._make_layer(block, 64, layers[0]) self.layer2 = self._make_layer(block, 128, layers[1], stride=2) self.layer3 = self._make_layer(block, 256, layers[2], stride=2) self.layer4 = self._make_layer(block, 512, layers[3], stride=2) # used for deconv layers self.deconv_layers = self._make_deconv_layer( 3, [256, 256, 256], [4, 4, 4], ) # self.final_layer = [] for head in sorted(self.heads): num_output = self.heads[head] if head_conv > 0: fc = nn.Sequential( nn.Conv2d(256, head_conv, kernel_size=3, padding=1, bias=True), nn.ReLU(inplace=True), nn.Conv2d(head_conv, num_output, kernel_size=1, stride=1, padding=0)) else: fc = nn.Conv2d( in_channels=256, out_channels=num_output, kernel_size=1, stride=1, padding=0 ) self.__setattr__(head, fc) # self.final_layer = nn.ModuleList(self.final_layer) def _make_layer(self, block, planes, blocks, stride=1): downsample = None if stride != 1 or self.inplanes != planes * block.expansion: downsample = nn.Sequential( nn.Conv2d(self.inplanes, planes * block.expansion, kernel_size=1, stride=stride, bias=False), nn.BatchNorm2d(planes * block.expansion, momentum=BN_MOMENTUM), ) layers = [] layers.append(block(self.inplanes, planes, stride, downsample)) self.inplanes = planes * block.expansion for i in range(1, blocks): layers.append(block(self.inplanes, planes)) return nn.Sequential(*layers) def _get_deconv_cfg(self, deconv_kernel, index): if deconv_kernel == 4: padding = 1 output_padding = 0 elif deconv_kernel == 3: padding = 1 output_padding = 1 elif deconv_kernel == 2: padding = 0 output_padding = 0 return deconv_kernel, padding, output_padding def _make_deconv_layer(self, num_layers, num_filters, num_kernels): assert num_layers == len(num_filters), \ 'ERROR: num_deconv_layers is different len(num_deconv_filters)' assert num_layers == len(num_kernels), \ 'ERROR: num_deconv_layers is different len(num_deconv_filters)' layers = [] for i in range(num_layers): kernel, padding, output_padding = \ self._get_deconv_cfg(num_kernels[i], i) planes = num_filters[i] layers.append( nn.ConvTranspose2d( in_channels=self.inplanes, out_channels=planes, kernel_size=kernel, stride=2, padding=padding, output_padding=output_padding, bias=self.deconv_with_bias)) layers.append(nn.BatchNorm2d(planes, momentum=BN_MOMENTUM)) layers.append(nn.ReLU(inplace=True)) self.inplanes = planes return nn.Sequential(*layers) def forward(self, x): x = self.conv1(x) x = self.bn1(x) x = self.relu(x) x = self.maxpool(x) x = self.layer1(x) x = self.layer2(x) x = self.layer3(x) x = self.layer4(x) x = self.deconv_layers(x) ret = {} for head in self.heads: ret[head] = self.__getattr__(head)(x) return ret def init_weights(self, num_layers, pretrained=True): if pretrained: # print('=> init resnet deconv weights from normal distribution') for _, m in self.deconv_layers.named_modules(): if isinstance(m, nn.ConvTranspose2d): # print('=> init {}.weight as normal(0, 0.001)'.format(name)) # print('=> init {}.bias as 0'.format(name)) nn.init.normal_(m.weight, std=0.001) if self.deconv_with_bias: nn.init.constant_(m.bias, 0) elif isinstance(m, nn.BatchNorm2d): # print('=> init {}.weight as 1'.format(name)) # print('=> init {}.bias as 0'.format(name)) nn.init.constant_(m.weight, 1) nn.init.constant_(m.bias, 0) # print('=> init final conv weights from normal distribution') for head in self.heads: final_layer = self.__getattr__(head) for i, m in enumerate(final_layer.modules()): if isinstance(m, nn.Conv2d): # nn.init.kaiming_normal_(m.weight, mode='fan_out', nonlinearity='relu') # print('=> init {}.weight as normal(0, 0.001)'.format(name)) # print('=> init {}.bias as 0'.format(name)) if m.weight.shape[0] == self.heads[head]: if 'hm' in head: nn.init.constant_(m.bias, -2.19) else: nn.init.normal_(m.weight, std=0.001) nn.init.constant_(m.bias, 0) # pretrained_state_dict = torch.load(pretrained) url = model_urls['resnet{}'.format(num_layers)] pretrained_state_dict = model_zoo.load_url(url) print('=> loading pretrained model {}'.format(url)) self.load_state_dict(pretrained_state_dict, strict=False) resnet_spec = {18: (BasicBlock, [2, 2, 2, 2]), 34: (BasicBlock, [3, 4, 6, 3]), 50: (Bottleneck, [3, 4, 6, 3]), 101: (Bottleneck, [3, 4, 23, 3]), 152: (Bottleneck, [3, 8, 36, 3])} def get_pose_net(num_layers, heads, head_conv, imagenet_pretrained): block_class, layers = resnet_spec[num_layers] model = PoseResNet(block_class, layers, heads, head_conv=head_conv) model.init_weights(num_layers, pretrained=imagenet_pretrained) return model