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| import math | |
| import torch.nn as nn | |
| from .splat import SplAtConv2d, DropBlock2D | |
| from utils.learning import freeze_params | |
| __all__ = ['ResNet', 'Bottleneck'] | |
| _url_format = 'https://s3.us-west-1.wasabisys.com/resnest/torch/{}-{}.pth' | |
| _model_sha256 = {name: checksum for checksum, name in []} | |
| def short_hash(name): | |
| if name not in _model_sha256: | |
| raise ValueError( | |
| 'Pretrained model for {name} is not available.'.format(name=name)) | |
| return _model_sha256[name][:8] | |
| resnest_model_urls = { | |
| name: _url_format.format(name, short_hash(name)) | |
| for name in _model_sha256.keys() | |
| } | |
| class GlobalAvgPool2d(nn.Module): | |
| def __init__(self): | |
| """Global average pooling over the input's spatial dimensions""" | |
| super(GlobalAvgPool2d, self).__init__() | |
| def forward(self, inputs): | |
| return nn.functional.adaptive_avg_pool2d(inputs, | |
| 1).view(inputs.size(0), -1) | |
| class Bottleneck(nn.Module): | |
| """ResNet Bottleneck | |
| """ | |
| # pylint: disable=unused-argument | |
| expansion = 4 | |
| def __init__(self, | |
| inplanes, | |
| planes, | |
| stride=1, | |
| downsample=None, | |
| radix=1, | |
| cardinality=1, | |
| bottleneck_width=64, | |
| avd=False, | |
| avd_first=False, | |
| dilation=1, | |
| is_first=False, | |
| rectified_conv=False, | |
| rectify_avg=False, | |
| norm_layer=None, | |
| dropblock_prob=0.0, | |
| last_gamma=False): | |
| super(Bottleneck, self).__init__() | |
| group_width = int(planes * (bottleneck_width / 64.)) * cardinality | |
| self.conv1 = nn.Conv2d(inplanes, | |
| group_width, | |
| kernel_size=1, | |
| bias=False) | |
| self.bn1 = norm_layer(group_width) | |
| self.dropblock_prob = dropblock_prob | |
| self.radix = radix | |
| self.avd = avd and (stride > 1 or is_first) | |
| self.avd_first = avd_first | |
| if self.avd: | |
| self.avd_layer = nn.AvgPool2d(3, stride, padding=1) | |
| stride = 1 | |
| if dropblock_prob > 0.0: | |
| self.dropblock1 = DropBlock2D(dropblock_prob, 3) | |
| if radix == 1: | |
| self.dropblock2 = DropBlock2D(dropblock_prob, 3) | |
| self.dropblock3 = DropBlock2D(dropblock_prob, 3) | |
| if radix >= 1: | |
| self.conv2 = SplAtConv2d(group_width, | |
| group_width, | |
| kernel_size=3, | |
| stride=stride, | |
| padding=dilation, | |
| dilation=dilation, | |
| groups=cardinality, | |
| bias=False, | |
| radix=radix, | |
| rectify=rectified_conv, | |
| rectify_avg=rectify_avg, | |
| norm_layer=norm_layer, | |
| dropblock_prob=dropblock_prob) | |
| elif rectified_conv: | |
| from rfconv import RFConv2d | |
| self.conv2 = RFConv2d(group_width, | |
| group_width, | |
| kernel_size=3, | |
| stride=stride, | |
| padding=dilation, | |
| dilation=dilation, | |
| groups=cardinality, | |
| bias=False, | |
| average_mode=rectify_avg) | |
| self.bn2 = norm_layer(group_width) | |
| else: | |
| self.conv2 = nn.Conv2d(group_width, | |
| group_width, | |
| kernel_size=3, | |
| stride=stride, | |
| padding=dilation, | |
| dilation=dilation, | |
| groups=cardinality, | |
| bias=False) | |
| self.bn2 = norm_layer(group_width) | |
| self.conv3 = nn.Conv2d(group_width, | |
| planes * 4, | |
| kernel_size=1, | |
| bias=False) | |
| self.bn3 = norm_layer(planes * 4) | |
| if last_gamma: | |
| from torch.nn.init import zeros_ | |
| zeros_(self.bn3.weight) | |
| self.relu = nn.ReLU(inplace=True) | |
| self.downsample = downsample | |
| self.dilation = dilation | |
| self.stride = stride | |
| def forward(self, x): | |
| residual = x | |
| out = self.conv1(x) | |
| out = self.bn1(out) | |
| if self.dropblock_prob > 0.0: | |
| out = self.dropblock1(out) | |
| out = self.relu(out) | |
| if self.avd and self.avd_first: | |
| out = self.avd_layer(out) | |
| out = self.conv2(out) | |
| if self.radix == 0: | |
| out = self.bn2(out) | |
| if self.dropblock_prob > 0.0: | |
| out = self.dropblock2(out) | |
| out = self.relu(out) | |
| if self.avd and not self.avd_first: | |
| out = self.avd_layer(out) | |
| out = self.conv3(out) | |
| out = self.bn3(out) | |
| if self.dropblock_prob > 0.0: | |
| out = self.dropblock3(out) | |
| if self.downsample is not None: | |
| residual = self.downsample(x) | |
| out += residual | |
| out = self.relu(out) | |
| return out | |
| class ResNet(nn.Module): | |
| """ResNet Variants | |
| Parameters | |
| ---------- | |
| block : Block | |
| Class for the residual block. Options are BasicBlockV1, BottleneckV1. | |
| layers : list of int | |
| Numbers of layers in each block | |
| classes : int, default 1000 | |
| Number of classification classes. | |
| dilated : bool, default False | |
| Applying dilation strategy to pretrained ResNet yielding a stride-8 model, | |
| typically used in Semantic Segmentation. | |
| norm_layer : object | |
| Normalization layer used in backbone network (default: :class:`mxnet.gluon.nn.BatchNorm`; | |
| for Synchronized Cross-GPU BachNormalization). | |
| Reference: | |
| - He, Kaiming, et al. "Deep residual learning for image recognition." Proceedings of the IEEE conference on computer vision and pattern recognition. 2016. | |
| - Yu, Fisher, and Vladlen Koltun. "Multi-scale context aggregation by dilated convolutions." | |
| """ | |
| # pylint: disable=unused-variable | |
| def __init__(self, | |
| block, | |
| layers, | |
| radix=1, | |
| groups=1, | |
| bottleneck_width=64, | |
| num_classes=1000, | |
| dilated=False, | |
| dilation=1, | |
| deep_stem=False, | |
| stem_width=64, | |
| avg_down=False, | |
| rectified_conv=False, | |
| rectify_avg=False, | |
| avd=False, | |
| avd_first=False, | |
| final_drop=0.0, | |
| dropblock_prob=0, | |
| last_gamma=False, | |
| norm_layer=nn.BatchNorm2d, | |
| freeze_at=0): | |
| self.cardinality = groups | |
| self.bottleneck_width = bottleneck_width | |
| # ResNet-D params | |
| self.inplanes = stem_width * 2 if deep_stem else 64 | |
| self.avg_down = avg_down | |
| self.last_gamma = last_gamma | |
| # ResNeSt params | |
| self.radix = radix | |
| self.avd = avd | |
| self.avd_first = avd_first | |
| super(ResNet, self).__init__() | |
| self.rectified_conv = rectified_conv | |
| self.rectify_avg = rectify_avg | |
| if rectified_conv: | |
| from rfconv import RFConv2d | |
| conv_layer = RFConv2d | |
| else: | |
| conv_layer = nn.Conv2d | |
| conv_kwargs = {'average_mode': rectify_avg} if rectified_conv else {} | |
| if deep_stem: | |
| self.conv1 = nn.Sequential( | |
| conv_layer(3, | |
| stem_width, | |
| kernel_size=3, | |
| stride=2, | |
| padding=1, | |
| bias=False, | |
| **conv_kwargs), | |
| norm_layer(stem_width), | |
| nn.ReLU(inplace=True), | |
| conv_layer(stem_width, | |
| stem_width, | |
| kernel_size=3, | |
| stride=1, | |
| padding=1, | |
| bias=False, | |
| **conv_kwargs), | |
| norm_layer(stem_width), | |
| nn.ReLU(inplace=True), | |
| conv_layer(stem_width, | |
| stem_width * 2, | |
| kernel_size=3, | |
| stride=1, | |
| padding=1, | |
| bias=False, | |
| **conv_kwargs), | |
| ) | |
| else: | |
| self.conv1 = conv_layer(3, | |
| 64, | |
| kernel_size=7, | |
| stride=2, | |
| padding=3, | |
| bias=False, | |
| **conv_kwargs) | |
| self.bn1 = norm_layer(self.inplanes) | |
| 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], | |
| norm_layer=norm_layer, | |
| is_first=False) | |
| self.layer2 = self._make_layer(block, | |
| 128, | |
| layers[1], | |
| stride=2, | |
| norm_layer=norm_layer) | |
| if dilated or dilation == 4: | |
| self.layer3 = self._make_layer(block, | |
| 256, | |
| layers[2], | |
| stride=1, | |
| dilation=2, | |
| norm_layer=norm_layer, | |
| dropblock_prob=dropblock_prob) | |
| elif dilation == 2: | |
| self.layer3 = self._make_layer(block, | |
| 256, | |
| layers[2], | |
| stride=2, | |
| dilation=1, | |
| norm_layer=norm_layer, | |
| dropblock_prob=dropblock_prob) | |
| else: | |
| self.layer3 = self._make_layer(block, | |
| 256, | |
| layers[2], | |
| stride=2, | |
| norm_layer=norm_layer, | |
| dropblock_prob=dropblock_prob) | |
| self.stem = [self.conv1, self.bn1] | |
| self.stages = [self.layer1, self.layer2, self.layer3] | |
| for m in self.modules(): | |
| if isinstance(m, nn.Conv2d): | |
| n = m.kernel_size[0] * m.kernel_size[1] * m.out_channels | |
| m.weight.data.normal_(0, math.sqrt(2. / n)) | |
| elif isinstance(m, norm_layer): | |
| m.weight.data.fill_(1) | |
| m.bias.data.zero_() | |
| self.freeze(freeze_at) | |
| def _make_layer(self, | |
| block, | |
| planes, | |
| blocks, | |
| stride=1, | |
| dilation=1, | |
| norm_layer=None, | |
| dropblock_prob=0.0, | |
| is_first=True): | |
| downsample = None | |
| if stride != 1 or self.inplanes != planes * block.expansion: | |
| down_layers = [] | |
| if self.avg_down: | |
| if dilation == 1: | |
| down_layers.append( | |
| nn.AvgPool2d(kernel_size=stride, | |
| stride=stride, | |
| ceil_mode=True, | |
| count_include_pad=False)) | |
| else: | |
| down_layers.append( | |
| nn.AvgPool2d(kernel_size=1, | |
| stride=1, | |
| ceil_mode=True, | |
| count_include_pad=False)) | |
| down_layers.append( | |
| nn.Conv2d(self.inplanes, | |
| planes * block.expansion, | |
| kernel_size=1, | |
| stride=1, | |
| bias=False)) | |
| else: | |
| down_layers.append( | |
| nn.Conv2d(self.inplanes, | |
| planes * block.expansion, | |
| kernel_size=1, | |
| stride=stride, | |
| bias=False)) | |
| down_layers.append(norm_layer(planes * block.expansion)) | |
| downsample = nn.Sequential(*down_layers) | |
| layers = [] | |
| if dilation == 1 or dilation == 2: | |
| layers.append( | |
| block(self.inplanes, | |
| planes, | |
| stride, | |
| downsample=downsample, | |
| radix=self.radix, | |
| cardinality=self.cardinality, | |
| bottleneck_width=self.bottleneck_width, | |
| avd=self.avd, | |
| avd_first=self.avd_first, | |
| dilation=1, | |
| is_first=is_first, | |
| rectified_conv=self.rectified_conv, | |
| rectify_avg=self.rectify_avg, | |
| norm_layer=norm_layer, | |
| dropblock_prob=dropblock_prob, | |
| last_gamma=self.last_gamma)) | |
| elif dilation == 4: | |
| layers.append( | |
| block(self.inplanes, | |
| planes, | |
| stride, | |
| downsample=downsample, | |
| radix=self.radix, | |
| cardinality=self.cardinality, | |
| bottleneck_width=self.bottleneck_width, | |
| avd=self.avd, | |
| avd_first=self.avd_first, | |
| dilation=2, | |
| is_first=is_first, | |
| rectified_conv=self.rectified_conv, | |
| rectify_avg=self.rectify_avg, | |
| norm_layer=norm_layer, | |
| dropblock_prob=dropblock_prob, | |
| last_gamma=self.last_gamma)) | |
| else: | |
| raise RuntimeError("=> unknown dilation size: {}".format(dilation)) | |
| self.inplanes = planes * block.expansion | |
| for i in range(1, blocks): | |
| layers.append( | |
| block(self.inplanes, | |
| planes, | |
| radix=self.radix, | |
| cardinality=self.cardinality, | |
| bottleneck_width=self.bottleneck_width, | |
| avd=self.avd, | |
| avd_first=self.avd_first, | |
| dilation=dilation, | |
| rectified_conv=self.rectified_conv, | |
| rectify_avg=self.rectify_avg, | |
| norm_layer=norm_layer, | |
| dropblock_prob=dropblock_prob, | |
| last_gamma=self.last_gamma)) | |
| return nn.Sequential(*layers) | |
| def forward(self, x): | |
| x = self.conv1(x) | |
| x = self.bn1(x) | |
| x = self.relu(x) | |
| x = self.maxpool(x) | |
| xs = [] | |
| x = self.layer1(x) | |
| xs.append(x) # 4X | |
| x = self.layer2(x) | |
| xs.append(x) # 8X | |
| x = self.layer3(x) | |
| xs.append(x) # 16X | |
| # Following STMVOS, we drop stage 5. | |
| xs.append(x) # 16X | |
| return xs | |
| def freeze(self, freeze_at): | |
| if freeze_at >= 1: | |
| for m in self.stem: | |
| freeze_params(m) | |
| for idx, stage in enumerate(self.stages, start=2): | |
| if freeze_at >= idx: | |
| freeze_params(stage) | |