diff --git a/networks/__pycache__/vit_seg_configs.cpython-37.pyc b/networks/__pycache__/vit_seg_configs.cpython-37.pyc new file mode 100644 index 0000000..e8034be Binary files /dev/null and b/networks/__pycache__/vit_seg_configs.cpython-37.pyc differ diff --git a/networks/__pycache__/vit_seg_modeling.cpython-37.pyc b/networks/__pycache__/vit_seg_modeling.cpython-37.pyc new file mode 100644 index 0000000..37a7336 Binary files /dev/null and b/networks/__pycache__/vit_seg_modeling.cpython-37.pyc differ diff --git a/networks/__pycache__/vit_seg_modeling_resnet_skip.cpython-37.pyc b/networks/__pycache__/vit_seg_modeling_resnet_skip.cpython-37.pyc new file mode 100644 index 0000000..6486c30 Binary files /dev/null and b/networks/__pycache__/vit_seg_modeling_resnet_skip.cpython-37.pyc differ diff --git a/networks/vit_seg_configs.py b/networks/vit_seg_configs.py new file mode 100644 index 0000000..1bc4c78 --- /dev/null +++ b/networks/vit_seg_configs.py @@ -0,0 +1,130 @@ +import ml_collections + +def get_b16_config(): + """Returns the ViT-B/16 configuration.""" + config = ml_collections.ConfigDict() + config.patches = ml_collections.ConfigDict({'size': (16, 16)}) + config.hidden_size = 768 + config.transformer = ml_collections.ConfigDict() + config.transformer.mlp_dim = 3072 + config.transformer.num_heads = 12 + config.transformer.num_layers = 12 + config.transformer.attention_dropout_rate = 0.0 + config.transformer.dropout_rate = 0.1 + + config.classifier = 'seg' + config.representation_size = None + config.resnet_pretrained_path = None + config.pretrained_path = '../model/vit_checkpoint/imagenet21k/ViT-B_16.npz' + config.patch_size = 16 + + config.decoder_channels = (256, 128, 64, 16) + config.n_classes = 2 + config.activation = 'softmax' + return config + + +def get_testing(): + """Returns a minimal configuration for testing.""" + config = ml_collections.ConfigDict() + config.patches = ml_collections.ConfigDict({'size': (16, 16)}) + config.hidden_size = 1 + config.transformer = ml_collections.ConfigDict() + config.transformer.mlp_dim = 1 + config.transformer.num_heads = 1 + config.transformer.num_layers = 1 + config.transformer.attention_dropout_rate = 0.0 + config.transformer.dropout_rate = 0.1 + config.classifier = 'token' + config.representation_size = None + return config + +def get_r50_b16_config(): + """Returns the Resnet50 + ViT-B/16 configuration.""" + config = get_b16_config() + config.patches.grid = (16, 16) + config.resnet = ml_collections.ConfigDict() + config.resnet.num_layers = (3, 4, 9) + config.resnet.width_factor = 1 + + config.classifier = 'seg' + config.pretrained_path = '../model/vit_checkpoint/imagenet21k/R50+ViT-B_16.npz' + config.decoder_channels = (256, 128, 64, 16) + config.skip_channels = [512, 256, 64, 16] + config.n_classes = 2 + config.n_skip = 3 + config.activation = 'softmax' + + return config + + +def get_b32_config(): + """Returns the ViT-B/32 configuration.""" + config = get_b16_config() + config.patches.size = (32, 32) + config.pretrained_path = '../model/vit_checkpoint/imagenet21k/ViT-B_32.npz' + return config + + +def get_l16_config(): + """Returns the ViT-L/16 configuration.""" + config = ml_collections.ConfigDict() + config.patches = ml_collections.ConfigDict({'size': (16, 16)}) + config.hidden_size = 1024 + config.transformer = ml_collections.ConfigDict() + config.transformer.mlp_dim = 4096 + config.transformer.num_heads = 16 + config.transformer.num_layers = 24 + config.transformer.attention_dropout_rate = 0.0 + config.transformer.dropout_rate = 0.1 + config.representation_size = None + + # custom + config.classifier = 'seg' + config.resnet_pretrained_path = None + config.pretrained_path = '../model/vit_checkpoint/imagenet21k/ViT-L_16.npz' + config.decoder_channels = (256, 128, 64, 16) + config.n_classes = 2 + config.activation = 'softmax' + return config + + +def get_r50_l16_config(): + """Returns the Resnet50 + ViT-L/16 configuration. customized """ + config = get_l16_config() + config.patches.grid = (16, 16) + config.resnet = ml_collections.ConfigDict() + config.resnet.num_layers = (3, 4, 9) + config.resnet.width_factor = 1 + + config.classifier = 'seg' + config.resnet_pretrained_path = '../model/vit_checkpoint/imagenet21k/R50+ViT-B_16.npz' + config.decoder_channels = (256, 128, 64, 16) + config.skip_channels = [512, 256, 64, 16] + config.n_classes = 2 + config.activation = 'softmax' + return config + + +def get_l32_config(): + """Returns the ViT-L/32 configuration.""" + config = get_l16_config() + config.patches.size = (32, 32) + return config + + +def get_h14_config(): + """Returns the ViT-L/16 configuration.""" + config = ml_collections.ConfigDict() + config.patches = ml_collections.ConfigDict({'size': (14, 14)}) + config.hidden_size = 1280 + config.transformer = ml_collections.ConfigDict() + config.transformer.mlp_dim = 5120 + config.transformer.num_heads = 16 + config.transformer.num_layers = 32 + config.transformer.attention_dropout_rate = 0.0 + config.transformer.dropout_rate = 0.1 + config.classifier = 'token' + config.representation_size = None + + return config diff --git a/networks/vit_seg_modeling.py b/networks/vit_seg_modeling.py new file mode 100644 index 0000000..8346d9f --- /dev/null +++ b/networks/vit_seg_modeling.py @@ -0,0 +1,453 @@ +# coding=utf-8 +from __future__ import absolute_import +from __future__ import division +from __future__ import print_function + +import copy +import logging +import math + +from os.path import join as pjoin + +import torch +import torch.nn as nn +import numpy as np + +from torch.nn import CrossEntropyLoss, Dropout, Softmax, Linear, Conv2d, LayerNorm +from torch.nn.modules.utils import _pair +from scipy import ndimage +from . import vit_seg_configs as configs +from .vit_seg_modeling_resnet_skip import ResNetV2 + + +logger = logging.getLogger(__name__) + + +ATTENTION_Q = "MultiHeadDotProductAttention_1/query" +ATTENTION_K = "MultiHeadDotProductAttention_1/key" +ATTENTION_V = "MultiHeadDotProductAttention_1/value" +ATTENTION_OUT = "MultiHeadDotProductAttention_1/out" +FC_0 = "MlpBlock_3/Dense_0" +FC_1 = "MlpBlock_3/Dense_1" +ATTENTION_NORM = "LayerNorm_0" +MLP_NORM = "LayerNorm_2" + + +def np2th(weights, conv=False): + """Possibly convert HWIO to OIHW.""" + if conv: + weights = weights.transpose([3, 2, 0, 1]) + return torch.from_numpy(weights) + + +def swish(x): + return x * torch.sigmoid(x) + + +ACT2FN = {"gelu": torch.nn.functional.gelu, "relu": torch.nn.functional.relu, "swish": swish} + + +class Attention(nn.Module): + def __init__(self, config, vis): + super(Attention, self).__init__() + self.vis = vis + self.num_attention_heads = config.transformer["num_heads"] + self.attention_head_size = int(config.hidden_size / self.num_attention_heads) + self.all_head_size = self.num_attention_heads * self.attention_head_size + + self.query = Linear(config.hidden_size, self.all_head_size) + self.key = Linear(config.hidden_size, self.all_head_size) + self.value = Linear(config.hidden_size, self.all_head_size) + + self.out = Linear(config.hidden_size, config.hidden_size) + self.attn_dropout = Dropout(config.transformer["attention_dropout_rate"]) + self.proj_dropout = Dropout(config.transformer["attention_dropout_rate"]) + + self.softmax = Softmax(dim=-1) + + def transpose_for_scores(self, x): + new_x_shape = x.size()[:-1] + (self.num_attention_heads, self.attention_head_size) + x = x.view(*new_x_shape) + return x.permute(0, 2, 1, 3) + + def forward(self, hidden_states): + mixed_query_layer = self.query(hidden_states) + mixed_key_layer = self.key(hidden_states) + mixed_value_layer = self.value(hidden_states) + + query_layer = self.transpose_for_scores(mixed_query_layer) + key_layer = self.transpose_for_scores(mixed_key_layer) + value_layer = self.transpose_for_scores(mixed_value_layer) + + attention_scores = torch.matmul(query_layer, key_layer.transpose(-1, -2)) + attention_scores = attention_scores / math.sqrt(self.attention_head_size) + attention_probs = self.softmax(attention_scores) + weights = attention_probs if self.vis else None + attention_probs = self.attn_dropout(attention_probs) + + context_layer = torch.matmul(attention_probs, value_layer) + context_layer = context_layer.permute(0, 2, 1, 3).contiguous() + new_context_layer_shape = context_layer.size()[:-2] + (self.all_head_size,) + context_layer = context_layer.view(*new_context_layer_shape) + attention_output = self.out(context_layer) + attention_output = self.proj_dropout(attention_output) + return attention_output, weights + + +class Mlp(nn.Module): + def __init__(self, config): + super(Mlp, self).__init__() + self.fc1 = Linear(config.hidden_size, config.transformer["mlp_dim"]) + self.fc2 = Linear(config.transformer["mlp_dim"], config.hidden_size) + self.act_fn = ACT2FN["gelu"] + self.dropout = Dropout(config.transformer["dropout_rate"]) + + self._init_weights() + + def _init_weights(self): + nn.init.xavier_uniform_(self.fc1.weight) + nn.init.xavier_uniform_(self.fc2.weight) + nn.init.normal_(self.fc1.bias, std=1e-6) + nn.init.normal_(self.fc2.bias, std=1e-6) + + def forward(self, x): + x = self.fc1(x) + x = self.act_fn(x) + x = self.dropout(x) + x = self.fc2(x) + x = self.dropout(x) + return x + + +class Embeddings(nn.Module): + """Construct the embeddings from patch, position embeddings. + """ + def __init__(self, config, img_size, in_channels=3): + super(Embeddings, self).__init__() + self.hybrid = None + self.config = config + img_size = _pair(img_size) + + if config.patches.get("grid") is not None: # ResNet + grid_size = config.patches["grid"] + patch_size = (img_size[0] // 16 // grid_size[0], img_size[1] // 16 // grid_size[1]) + patch_size_real = (patch_size[0] * 16, patch_size[1] * 16) + n_patches = (img_size[0] // patch_size_real[0]) * (img_size[1] // patch_size_real[1]) + self.hybrid = True + else: + patch_size = _pair(config.patches["size"]) + n_patches = (img_size[0] // patch_size[0]) * (img_size[1] // patch_size[1]) + self.hybrid = False + + if self.hybrid: + self.hybrid_model = ResNetV2(block_units=config.resnet.num_layers, width_factor=config.resnet.width_factor) + in_channels = self.hybrid_model.width * 16 + self.patch_embeddings = Conv2d(in_channels=in_channels, + out_channels=config.hidden_size, + kernel_size=patch_size, + stride=patch_size) + self.position_embeddings = nn.Parameter(torch.zeros(1, n_patches, config.hidden_size)) + + self.dropout = Dropout(config.transformer["dropout_rate"]) + + + def forward(self, x): + if self.hybrid: + x, features = self.hybrid_model(x) + else: + features = None + x = self.patch_embeddings(x) # (B, hidden. n_patches^(1/2), n_patches^(1/2)) + x = x.flatten(2) + x = x.transpose(-1, -2) # (B, n_patches, hidden) + + embeddings = x + self.position_embeddings + embeddings = self.dropout(embeddings) + return embeddings, features + + +class Block(nn.Module): + def __init__(self, config, vis): + super(Block, self).__init__() + self.hidden_size = config.hidden_size + self.attention_norm = LayerNorm(config.hidden_size, eps=1e-6) + self.ffn_norm = LayerNorm(config.hidden_size, eps=1e-6) + self.ffn = Mlp(config) + self.attn = Attention(config, vis) + + def forward(self, x): + h = x + x = self.attention_norm(x) + x, weights = self.attn(x) + x = x + h + + h = x + x = self.ffn_norm(x) + x = self.ffn(x) + x = x + h + return x, weights + + def load_from(self, weights, n_block): + ROOT = f"Transformer/encoderblock_{n_block}" + with torch.no_grad(): + query_weight = np2th(weights[pjoin(ROOT, ATTENTION_Q, "kernel")]).view(self.hidden_size, self.hidden_size).t() + key_weight = np2th(weights[pjoin(ROOT, ATTENTION_K, "kernel")]).view(self.hidden_size, self.hidden_size).t() + value_weight = np2th(weights[pjoin(ROOT, ATTENTION_V, "kernel")]).view(self.hidden_size, self.hidden_size).t() + out_weight = np2th(weights[pjoin(ROOT, ATTENTION_OUT, "kernel")]).view(self.hidden_size, self.hidden_size).t() + + query_bias = np2th(weights[pjoin(ROOT, ATTENTION_Q, "bias")]).view(-1) + key_bias = np2th(weights[pjoin(ROOT, ATTENTION_K, "bias")]).view(-1) + value_bias = np2th(weights[pjoin(ROOT, ATTENTION_V, "bias")]).view(-1) + out_bias = np2th(weights[pjoin(ROOT, ATTENTION_OUT, "bias")]).view(-1) + + self.attn.query.weight.copy_(query_weight) + self.attn.key.weight.copy_(key_weight) + self.attn.value.weight.copy_(value_weight) + self.attn.out.weight.copy_(out_weight) + self.attn.query.bias.copy_(query_bias) + self.attn.key.bias.copy_(key_bias) + self.attn.value.bias.copy_(value_bias) + self.attn.out.bias.copy_(out_bias) + + mlp_weight_0 = np2th(weights[pjoin(ROOT, FC_0, "kernel")]).t() + mlp_weight_1 = np2th(weights[pjoin(ROOT, FC_1, "kernel")]).t() + mlp_bias_0 = np2th(weights[pjoin(ROOT, FC_0, "bias")]).t() + mlp_bias_1 = np2th(weights[pjoin(ROOT, FC_1, "bias")]).t() + + self.ffn.fc1.weight.copy_(mlp_weight_0) + self.ffn.fc2.weight.copy_(mlp_weight_1) + self.ffn.fc1.bias.copy_(mlp_bias_0) + self.ffn.fc2.bias.copy_(mlp_bias_1) + + self.attention_norm.weight.copy_(np2th(weights[pjoin(ROOT, ATTENTION_NORM, "scale")])) + self.attention_norm.bias.copy_(np2th(weights[pjoin(ROOT, ATTENTION_NORM, "bias")])) + self.ffn_norm.weight.copy_(np2th(weights[pjoin(ROOT, MLP_NORM, "scale")])) + self.ffn_norm.bias.copy_(np2th(weights[pjoin(ROOT, MLP_NORM, "bias")])) + + +class Encoder(nn.Module): + def __init__(self, config, vis): + super(Encoder, self).__init__() + self.vis = vis + self.layer = nn.ModuleList() + self.encoder_norm = LayerNorm(config.hidden_size, eps=1e-6) + for _ in range(config.transformer["num_layers"]): + layer = Block(config, vis) + self.layer.append(copy.deepcopy(layer)) + + def forward(self, hidden_states): + attn_weights = [] + for layer_block in self.layer: + hidden_states, weights = layer_block(hidden_states) + if self.vis: + attn_weights.append(weights) + encoded = self.encoder_norm(hidden_states) + return encoded, attn_weights + + +class Transformer(nn.Module): + def __init__(self, config, img_size, vis): + super(Transformer, self).__init__() + self.embeddings = Embeddings(config, img_size=img_size) + self.encoder = Encoder(config, vis) + + def forward(self, input_ids): + embedding_output, features = self.embeddings(input_ids) + encoded, attn_weights = self.encoder(embedding_output) # (B, n_patch, hidden) + return encoded, attn_weights, features + + +class Conv2dReLU(nn.Sequential): + def __init__( + self, + in_channels, + out_channels, + kernel_size, + padding=0, + stride=1, + use_batchnorm=True, + ): + conv = nn.Conv2d( + in_channels, + out_channels, + kernel_size, + stride=stride, + padding=padding, + bias=not (use_batchnorm), + ) + relu = nn.ReLU(inplace=True) + + bn = nn.BatchNorm2d(out_channels) + + super(Conv2dReLU, self).__init__(conv, bn, relu) + + +class DecoderBlock(nn.Module): + def __init__( + self, + in_channels, + out_channels, + skip_channels=0, + use_batchnorm=True, + ): + super().__init__() + self.conv1 = Conv2dReLU( + in_channels + skip_channels, + out_channels, + kernel_size=3, + padding=1, + use_batchnorm=use_batchnorm, + ) + self.conv2 = Conv2dReLU( + out_channels, + out_channels, + kernel_size=3, + padding=1, + use_batchnorm=use_batchnorm, + ) + self.up = nn.UpsamplingBilinear2d(scale_factor=2) + + def forward(self, x, skip=None): + x = self.up(x) + if skip is not None: + x = torch.cat([x, skip], dim=1) + x = self.conv1(x) + x = self.conv2(x) + return x + + +class SegmentationHead(nn.Sequential): + + def __init__(self, in_channels, out_channels, kernel_size=3, upsampling=1): + conv2d = nn.Conv2d(in_channels, out_channels, kernel_size=kernel_size, padding=kernel_size // 2) + upsampling = nn.UpsamplingBilinear2d(scale_factor=upsampling) if upsampling > 1 else nn.Identity() + super().__init__(conv2d, upsampling) + + +class DecoderCup(nn.Module): + def __init__(self, config): + super().__init__() + self.config = config + head_channels = 512 + self.conv_more = Conv2dReLU( + config.hidden_size, + head_channels, + kernel_size=3, + padding=1, + use_batchnorm=True, + ) + decoder_channels = config.decoder_channels + in_channels = [head_channels] + list(decoder_channels[:-1]) + out_channels = decoder_channels + + if self.config.n_skip != 0: + skip_channels = self.config.skip_channels + for i in range(4-self.config.n_skip): # re-select the skip channels according to n_skip + skip_channels[3-i]=0 + + else: + skip_channels=[0,0,0,0] + + blocks = [ + DecoderBlock(in_ch, out_ch, sk_ch) for in_ch, out_ch, sk_ch in zip(in_channels, out_channels, skip_channels) + ] + self.blocks = nn.ModuleList(blocks) + + def forward(self, hidden_states, features=None): + B, n_patch, hidden = hidden_states.size() # reshape from (B, n_patch, hidden) to (B, h, w, hidden) + h, w = int(np.sqrt(n_patch)), int(np.sqrt(n_patch)) + x = hidden_states.permute(0, 2, 1) + x = x.contiguous().view(B, hidden, h, w) + x = self.conv_more(x) + for i, decoder_block in enumerate(self.blocks): + if features is not None: + skip = features[i] if (i < self.config.n_skip) else None + else: + skip = None + x = decoder_block(x, skip=skip) + return x + + +class VisionTransformer(nn.Module): + def __init__(self, config, img_size=224, num_classes=21843, zero_head=False, vis=False): + super(VisionTransformer, self).__init__() + self.num_classes = num_classes + self.zero_head = zero_head + self.classifier = config.classifier + self.transformer = Transformer(config, img_size, vis) + self.decoder = DecoderCup(config) + self.segmentation_head = SegmentationHead( + in_channels=config['decoder_channels'][-1], + out_channels=config['n_classes'], + kernel_size=3, + ) + self.config = config + + def forward(self, x): + if x.size()[1] == 1: + x = x.repeat(1,3,1,1) + x, attn_weights, features = self.transformer(x) # (B, n_patch, hidden) + x = self.decoder(x, features) + logits = self.segmentation_head(x) + return logits + + def load_from(self, weights): + with torch.no_grad(): + + res_weight = weights + self.transformer.embeddings.patch_embeddings.weight.copy_(np2th(weights["embedding/kernel"], conv=True)) + self.transformer.embeddings.patch_embeddings.bias.copy_(np2th(weights["embedding/bias"])) + + self.transformer.encoder.encoder_norm.weight.copy_(np2th(weights["Transformer/encoder_norm/scale"])) + self.transformer.encoder.encoder_norm.bias.copy_(np2th(weights["Transformer/encoder_norm/bias"])) + + posemb = np2th(weights["Transformer/posembed_input/pos_embedding"]) + + posemb_new = self.transformer.embeddings.position_embeddings + if posemb.size() == posemb_new.size(): + self.transformer.embeddings.position_embeddings.copy_(posemb) + elif posemb.size()[1]-1 == posemb_new.size()[1]: + posemb = posemb[:, 1:] + self.transformer.embeddings.position_embeddings.copy_(posemb) + else: + logger.info("load_pretrained: resized variant: %s to %s" % (posemb.size(), posemb_new.size())) + ntok_new = posemb_new.size(1) + if self.classifier == "seg": + _, posemb_grid = posemb[:, :1], posemb[0, 1:] + gs_old = int(np.sqrt(len(posemb_grid))) + gs_new = int(np.sqrt(ntok_new)) + print('load_pretrained: grid-size from %s to %s' % (gs_old, gs_new)) + posemb_grid = posemb_grid.reshape(gs_old, gs_old, -1) + zoom = (gs_new / gs_old, gs_new / gs_old, 1) + posemb_grid = ndimage.zoom(posemb_grid, zoom, order=1) # th2np + posemb_grid = posemb_grid.reshape(1, gs_new * gs_new, -1) + posemb = posemb_grid + self.transformer.embeddings.position_embeddings.copy_(np2th(posemb)) + + # Encoder whole + for bname, block in self.transformer.encoder.named_children(): + for uname, unit in block.named_children(): + unit.load_from(weights, n_block=uname) + + if self.transformer.embeddings.hybrid: + self.transformer.embeddings.hybrid_model.root.conv.weight.copy_(np2th(res_weight["conv_root/kernel"], conv=True)) + gn_weight = np2th(res_weight["gn_root/scale"]).view(-1) + gn_bias = np2th(res_weight["gn_root/bias"]).view(-1) + self.transformer.embeddings.hybrid_model.root.gn.weight.copy_(gn_weight) + self.transformer.embeddings.hybrid_model.root.gn.bias.copy_(gn_bias) + + for bname, block in self.transformer.embeddings.hybrid_model.body.named_children(): + for uname, unit in block.named_children(): + unit.load_from(res_weight, n_block=bname, n_unit=uname) + +CONFIGS = { + 'ViT-B_16': configs.get_b16_config(), + 'ViT-B_32': configs.get_b32_config(), + 'ViT-L_16': configs.get_l16_config(), + 'ViT-L_32': configs.get_l32_config(), + 'ViT-H_14': configs.get_h14_config(), + 'R50-ViT-B_16': configs.get_r50_b16_config(), + 'R50-ViT-L_16': configs.get_r50_l16_config(), + 'testing': configs.get_testing(), +} + + diff --git a/networks/vit_seg_modeling_resnet_skip.py b/networks/vit_seg_modeling_resnet_skip.py new file mode 100644 index 0000000..9753d52 --- /dev/null +++ b/networks/vit_seg_modeling_resnet_skip.py @@ -0,0 +1,160 @@ +import math + +from os.path import join as pjoin +from collections import OrderedDict + +import torch +import torch.nn as nn +import torch.nn.functional as F + + +def np2th(weights, conv=False): + """Possibly convert HWIO to OIHW.""" + if conv: + weights = weights.transpose([3, 2, 0, 1]) + return torch.from_numpy(weights) + + +class StdConv2d(nn.Conv2d): + + def forward(self, x): + w = self.weight + v, m = torch.var_mean(w, dim=[1, 2, 3], keepdim=True, unbiased=False) + w = (w - m) / torch.sqrt(v + 1e-5) + return F.conv2d(x, w, self.bias, self.stride, self.padding, + self.dilation, self.groups) + + +def conv3x3(cin, cout, stride=1, groups=1, bias=False): + return StdConv2d(cin, cout, kernel_size=3, stride=stride, + padding=1, bias=bias, groups=groups) + + +def conv1x1(cin, cout, stride=1, bias=False): + return StdConv2d(cin, cout, kernel_size=1, stride=stride, + padding=0, bias=bias) + + +class PreActBottleneck(nn.Module): + """Pre-activation (v2) bottleneck block. + """ + + def __init__(self, cin, cout=None, cmid=None, stride=1): + super().__init__() + cout = cout or cin + cmid = cmid or cout//4 + + self.gn1 = nn.GroupNorm(32, cmid, eps=1e-6) + self.conv1 = conv1x1(cin, cmid, bias=False) + self.gn2 = nn.GroupNorm(32, cmid, eps=1e-6) + self.conv2 = conv3x3(cmid, cmid, stride, bias=False) # Original code has it on conv1!! + self.gn3 = nn.GroupNorm(32, cout, eps=1e-6) + self.conv3 = conv1x1(cmid, cout, bias=False) + self.relu = nn.ReLU(inplace=True) + + if (stride != 1 or cin != cout): + # Projection also with pre-activation according to paper. + self.downsample = conv1x1(cin, cout, stride, bias=False) + self.gn_proj = nn.GroupNorm(cout, cout) + + def forward(self, x): + + # Residual branch + residual = x + if hasattr(self, 'downsample'): + residual = self.downsample(x) + residual = self.gn_proj(residual) + + # Unit's branch + y = self.relu(self.gn1(self.conv1(x))) + y = self.relu(self.gn2(self.conv2(y))) + y = self.gn3(self.conv3(y)) + + y = self.relu(residual + y) + return y + + def load_from(self, weights, n_block, n_unit): + conv1_weight = np2th(weights[pjoin(n_block, n_unit, "conv1/kernel")], conv=True) + conv2_weight = np2th(weights[pjoin(n_block, n_unit, "conv2/kernel")], conv=True) + conv3_weight = np2th(weights[pjoin(n_block, n_unit, "conv3/kernel")], conv=True) + + gn1_weight = np2th(weights[pjoin(n_block, n_unit, "gn1/scale")]) + gn1_bias = np2th(weights[pjoin(n_block, n_unit, "gn1/bias")]) + + gn2_weight = np2th(weights[pjoin(n_block, n_unit, "gn2/scale")]) + gn2_bias = np2th(weights[pjoin(n_block, n_unit, "gn2/bias")]) + + gn3_weight = np2th(weights[pjoin(n_block, n_unit, "gn3/scale")]) + gn3_bias = np2th(weights[pjoin(n_block, n_unit, "gn3/bias")]) + + self.conv1.weight.copy_(conv1_weight) + self.conv2.weight.copy_(conv2_weight) + self.conv3.weight.copy_(conv3_weight) + + self.gn1.weight.copy_(gn1_weight.view(-1)) + self.gn1.bias.copy_(gn1_bias.view(-1)) + + self.gn2.weight.copy_(gn2_weight.view(-1)) + self.gn2.bias.copy_(gn2_bias.view(-1)) + + self.gn3.weight.copy_(gn3_weight.view(-1)) + self.gn3.bias.copy_(gn3_bias.view(-1)) + + if hasattr(self, 'downsample'): + proj_conv_weight = np2th(weights[pjoin(n_block, n_unit, "conv_proj/kernel")], conv=True) + proj_gn_weight = np2th(weights[pjoin(n_block, n_unit, "gn_proj/scale")]) + proj_gn_bias = np2th(weights[pjoin(n_block, n_unit, "gn_proj/bias")]) + + self.downsample.weight.copy_(proj_conv_weight) + self.gn_proj.weight.copy_(proj_gn_weight.view(-1)) + self.gn_proj.bias.copy_(proj_gn_bias.view(-1)) + +class ResNetV2(nn.Module): + """Implementation of Pre-activation (v2) ResNet mode.""" + + def __init__(self, block_units, width_factor): + super().__init__() + width = int(64 * width_factor) + self.width = width + + self.root = nn.Sequential(OrderedDict([ + ('conv', StdConv2d(3, width, kernel_size=7, stride=2, bias=False, padding=3)), + ('gn', nn.GroupNorm(32, width, eps=1e-6)), + ('relu', nn.ReLU(inplace=True)), + # ('pool', nn.MaxPool2d(kernel_size=3, stride=2, padding=0)) + ])) + + self.body = nn.Sequential(OrderedDict([ + ('block1', nn.Sequential(OrderedDict( + [('unit1', PreActBottleneck(cin=width, cout=width*4, cmid=width))] + + [(f'unit{i:d}', PreActBottleneck(cin=width*4, cout=width*4, cmid=width)) for i in range(2, block_units[0] + 1)], + ))), + ('block2', nn.Sequential(OrderedDict( + [('unit1', PreActBottleneck(cin=width*4, cout=width*8, cmid=width*2, stride=2))] + + [(f'unit{i:d}', PreActBottleneck(cin=width*8, cout=width*8, cmid=width*2)) for i in range(2, block_units[1] + 1)], + ))), + ('block3', nn.Sequential(OrderedDict( + [('unit1', PreActBottleneck(cin=width*8, cout=width*16, cmid=width*4, stride=2))] + + [(f'unit{i:d}', PreActBottleneck(cin=width*16, cout=width*16, cmid=width*4)) for i in range(2, block_units[2] + 1)], + ))), + ])) + + def forward(self, x): + features = [] + b, c, in_size, _ = x.size() + x = self.root(x) + features.append(x) + x = nn.MaxPool2d(kernel_size=3, stride=2, padding=0)(x) + for i in range(len(self.body)-1): + x = self.body[i](x) + right_size = int(in_size / 4 / (i+1)) + if x.size()[2] != right_size: + pad = right_size - x.size()[2] + assert pad < 3 and pad > 0, "x {} should {}".format(x.size(), right_size) + feat = torch.zeros((b, x.size()[1], right_size, right_size), device=x.device) + feat[:, :, 0:x.size()[2], 0:x.size()[3]] = x[:] + else: + feat = x + features.append(feat) + x = self.body[-1](x) + return x, features[::-1]