diff --git a/docs/zh_CN/models/ImageNet1k/SwinTransformerV2.md b/docs/zh_CN/models/ImageNet1k/SwinTransformerV2.md index f47c8812797dc5764474b282d675ec193aadce85..7815de4120bd7657efced43e84543501f4bae091 100644 --- a/docs/zh_CN/models/ImageNet1k/SwinTransformerV2.md +++ b/docs/zh_CN/models/ImageNet1k/SwinTransformerV2.md @@ -72,7 +72,7 @@ SwinTransformerV2 在 SwinTransformer 的基础上进行改进,可处理大尺 ## 3. 模型训练、评估和预测 -此部分内容包括训练环境配置、ImageNet数据的准备、SwinTransformer 在 ImageNet 上的训练、评估、预测等内容。在 `ppcls/configs/ImageNet/SwinTransformer/` 中提供了 SwinTransformer 的训练配置,可以通过如下脚本启动训练:此部分内容可以参考[ResNet50 模型训练、评估和预测](./ResNet.md#3)。 +此部分内容包括训练环境配置、ImageNet数据的准备、SwinTransformerV2 在 ImageNet 上的训练、评估、预测等内容。在 `ppcls/configs/ImageNet/SwinTransformerV2/` 中提供了 SwinTransformerV2 的训练配置,可以通过如下脚本启动训练:此部分内容可以参考[ResNet50 模型训练、评估和预测](./ResNet.md#3)。 **备注:** 由于 SwinTransformer 系列模型默认使用的 GPU 数量为 8 个,所以在训练时,需要指定8个GPU,如`python3 -m paddle.distributed.launch --gpus="0,1,2,3,4,5,6,7" tools/train.py -c xxx.yaml`, 如果使用 4 个 GPU 训练,默认学习率需要减小一半,精度可能有损。 diff --git a/ppcls/arch/backbone/__init__.py b/ppcls/arch/backbone/__init__.py index ac362642eafee78e77d13a99d5484b47898acebc..7aaf30f2ff789443b481428b1f022cb907dd776f 100644 --- a/ppcls/arch/backbone/__init__.py +++ b/ppcls/arch/backbone/__init__.py @@ -54,7 +54,7 @@ from .model_zoo.regnet import RegNetX_200MF, RegNetX_400MF, RegNetX_600MF, RegNe from .model_zoo.vision_transformer import ViT_small_patch16_224, ViT_base_patch16_224, ViT_base_patch16_384, ViT_base_patch32_384, ViT_large_patch16_224, ViT_large_patch16_384, ViT_large_patch32_384 from .model_zoo.distilled_vision_transformer import DeiT_tiny_patch16_224, DeiT_small_patch16_224, DeiT_base_patch16_224, DeiT_tiny_distilled_patch16_224, DeiT_small_distilled_patch16_224, DeiT_base_distilled_patch16_224, DeiT_base_patch16_384, DeiT_base_distilled_patch16_384 from .legendary_models.swin_transformer import SwinTransformer_tiny_patch4_window7_224, SwinTransformer_small_patch4_window7_224, SwinTransformer_base_patch4_window7_224, SwinTransformer_base_patch4_window12_384, SwinTransformer_large_patch4_window7_224, SwinTransformer_large_patch4_window12_384 -from .model_zoo.swin_transformerv2 import SwinTransformerV2_tiny_patch4_window8_256, SwinTransformerV2_small_patch4_window8_256, SwinTransformerV2_base_patch4_window8_256, SwinTransformerV2_tiny_patch4_window16_256, SwinTransformerV2_small_patch4_window16_256, SwinTransformerV2_base_patch4_window16_256, SwinTransformerV2_base_patch4_window12to16_256, SwinTransformerV2_base_patch4_window24_384, SwinTransformerV2_large_patch4_window16_256, SwinTransformerV2_large_patch4_window24_384 +from .model_zoo.swin_transformer_v2 import SwinTransformerV2_tiny_patch4_window8_256, SwinTransformerV2_small_patch4_window8_256, SwinTransformerV2_base_patch4_window8_256, SwinTransformerV2_tiny_patch4_window16_256, SwinTransformerV2_small_patch4_window16_256, SwinTransformerV2_base_patch4_window16_256, SwinTransformerV2_base_patch4_window24_384, SwinTransformerV2_large_patch4_window16_256, SwinTransformerV2_large_patch4_window24_384 from .model_zoo.cswin_transformer import CSWinTransformer_tiny_224, CSWinTransformer_small_224, CSWinTransformer_base_224, CSWinTransformer_large_224, CSWinTransformer_base_384, CSWinTransformer_large_384 from .model_zoo.mixnet import MixNet_S, MixNet_M, MixNet_L from .model_zoo.rexnet import ReXNet_1_0, ReXNet_1_3, ReXNet_1_5, ReXNet_2_0, ReXNet_3_0 diff --git a/ppcls/arch/backbone/model_zoo/swin_transformer_v2.py b/ppcls/arch/backbone/model_zoo/swin_transformer_v2.py new file mode 100644 index 0000000000000000000000000000000000000000..67a1b36e3859fd3d1cc58aceec073dfef3130f30 --- /dev/null +++ b/ppcls/arch/backbone/model_zoo/swin_transformer_v2.py @@ -0,0 +1,988 @@ +# copyright (c) 2023 PaddlePaddle Authors. All Rights Reserve. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +# Code was based on https://github.com/microsoft/Swin-Transformer +# reference: https://arxiv.org/abs/2111.09883 + +import paddle +import paddle.nn as nn +import paddle.nn.functional as F +from paddle.nn.initializer import TruncatedNormal, Constant, Normal +import numpy as np +import math + +from .vision_transformer import trunc_normal_, zeros_, ones_, to_2tuple, DropPath, Identity +from ..base.theseus_layer import TheseusLayer +from ....utils.save_load import load_dygraph_pretrain, load_dygraph_pretrain_from_url + +MODEL_URLS = { + "SwinTransformerV2_tiny_patch4_window8_256": + "https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/legendary_models/SwinTransformerV2_tiny_patch4_window8_256_pretrained.pdparams", + "SwinTransformerV2_tiny_patch4_window16_256": + "https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/legendary_models/SwinTransformerV2_tiny_patch4_window16_256_pretrained.pdparams", + "SwinTransformerV2_small_patch4_window8_256": + "https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/legendary_models/SwinTransformerV2_small_patch4_window8_256_pretrained.pdparams", + "SwinTransformerV2_small_patch4_window16_256": + "https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/legendary_models/SwinTransformerV2_small_patch4_window16_256_pretrained.pdparams", + "SwinTransformerV2_base_patch4_window8_256": + "https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/legendary_models/SwinTransformerV2_base_patch4_window8_256_pretrained.pdparams", + "SwinTransformerV2_base_patch4_window16_256": + "https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/legendary_models/SwinTransformerV2_base_patch4_window16_256_pretrained.pdparams", + "SwinTransformerV2_base_patch4_window24_384": + "https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/legendary_models/SwinTransformerV2_base_patch4_window24_384_pretrained.pdparams", + "SwinTransformerV2_large_patch4_window16_256": + "https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/legendary_models/SwinTransformerV2_large_patch4_window16_256_pretrained.pdparams", + "SwinTransformerV2_large_patch4_window24_384": + "https://paddle-imagenet-models-name.bj.bcebos.com/dygraph/legendary_models/SwinTransformerV2_large_patch4_window24_384_pretrained.pdparams" +} + +__all__ = list(MODEL_URLS.keys()) + + +class Mlp(nn.Layer): + def __init__(self, + in_features, + hidden_features=None, + out_features=None, + act_layer=nn.GELU, + drop=0.): + super().__init__() + out_features = out_features or in_features + hidden_features = hidden_features or in_features + self.fc1 = nn.Linear(in_features, hidden_features) + self.act = act_layer() + self.fc2 = nn.Linear(hidden_features, out_features) + self.drop = nn.Dropout(drop) + + def forward(self, x): + x = self.fc1(x) + x = self.act(x) + x = self.drop(x) + x = self.fc2(x) + x = self.drop(x) + return x + + +def masked_fill(x, mask, value): + y = paddle.full(x.shape, value, x.dtype) + return paddle.where(mask, y, x) + + +def window_partition(x, window_size): + """ + Args: + x: (B, H, W, C) + window_size (int): window size + + Returns: + windows: (num_windows*B, window_size, window_size, C) + """ + B, H, W, C = x.shape + x = x.reshape( + [B, H // window_size, window_size, W // window_size, window_size, C]) + windows = x.transpose(perm=[0, 1, 3, 2, 4, 5]).reshape( + [-1, window_size, window_size, C]) + return windows + + +def window_reverse(windows, window_size, H, W): + """ + Args: + windows: (num_windows*B, window_size, window_size, C) + window_size (int): Window size + H (int): Height of image + W (int): Width of image + + Returns: + x: (B, H, W, C) + """ + C = windows.shape[-1] + B = int(windows.shape[0] / (H * W / window_size / window_size)) + x = windows.reshape( + [-1, H // window_size, W // window_size, window_size, window_size, C]) + x = x.transpose(perm=[0, 1, 3, 2, 4, 5]).reshape([-1, H, W, C]) + return x + + +class WindowAttention(nn.Layer): + r""" Window based multi-head self attention (W-MSA) module with relative position bias. + It supports both of shifted and non-shifted window. + + Args: + dim (int): Number of input channels. + window_size (tuple[int]): The height and width of the window. + num_heads (int): Number of attention heads. + qkv_bias (bool, optional): If True, add a learnable bias to query, key, value. Default: True + attn_drop (float, optional): Dropout ratio of attention weight. Default: 0.0 + proj_drop (float, optional): Dropout ratio of output. Default: 0.0 + pretrained_window_size (tuple[int]): The height and width of the window in pre-training. + """ + + def __init__(self, + dim, + window_size, + num_heads, + qkv_bias=True, + attn_drop=0., + proj_drop=0., + pretrained_window_size=[0, 0]): + + super().__init__() + self.dim = dim + self.window_size = window_size # Wh, Ww + self.pretrained_window_size = pretrained_window_size + self.num_heads = num_heads + + self.logit_scale = self.create_parameter( + [num_heads, 1, 1], + dtype='float32', + default_initializer=Constant(math.log(10.))) + + # mlp to generate continuous relative position bias + self.cpb_mlp = nn.Sequential( + nn.Linear( + 2, 512, bias_attr=True), + nn.ReLU(), + nn.Linear( + 512, num_heads, bias_attr=False)) + + # get relative_coords_table + relative_coords_h = paddle.arange( + -(self.window_size[0] - 1), self.window_size[0], dtype='float32') + relative_coords_w = paddle.arange( + -(self.window_size[1] - 1), self.window_size[1], dtype='float32') + relative_coords_table = paddle.stack( + paddle.meshgrid([relative_coords_h, relative_coords_w])).transpose( + perm=[1, 2, 0]).unsqueeze(0) # 1, 2*Wh-1, 2*Ww-1, 2 + if pretrained_window_size[0] > 0: + relative_coords_table[:, :, :, 0] /= ( + pretrained_window_size[0] - 1) + relative_coords_table[:, :, :, 1] /= ( + pretrained_window_size[1] - 1) + else: + relative_coords_table[:, :, :, 0] /= (self.window_size[0] - 1) + relative_coords_table[:, :, :, 1] /= (self.window_size[1] - 1) + relative_coords_table *= 8 # normalize to -8, 8 + relative_coords_table = paddle.sign( + relative_coords_table) * paddle.log2( + paddle.abs(relative_coords_table) + 1.0) / np.log2(8) + + self.register_buffer("relative_coords_table", relative_coords_table) + + # get pair-wise relative position index for each token inside the window + coords_h = paddle.arange(self.window_size[0]) + coords_w = paddle.arange(self.window_size[1]) + coords = paddle.stack(paddle.meshgrid( + [coords_h, coords_w])) # 2, Wh, Ww + coords_flatten = paddle.flatten(coords, 1) # 2, Wh*Ww + relative_coords = coords_flatten[:, :, + None] - coords_flatten[:, + None, :] # 2, Wh*Ww, Wh*Ww + relative_coords = relative_coords.transpose( + perm=[1, 2, 0]) # Wh*Ww, Wh*Ww, 2 + relative_coords[:, :, 0] += self.window_size[ + 0] - 1 # shift to start from 0 + relative_coords[:, :, 1] += self.window_size[1] - 1 + relative_coords[:, :, 0] *= 2 * self.window_size[1] - 1 + relative_position_index = relative_coords.sum(-1) # Wh*Ww, Wh*Ww + self.register_buffer("relative_position_index", + relative_position_index) + + self.qkv = nn.Linear(dim, dim * 3, bias_attr=False) + if qkv_bias: + self.q_bias = self.create_parameter( + [dim], dtype='float32', default_initializer=zeros_) + self.v_bias = self.create_parameter( + [dim], dtype='float32', default_initializer=zeros_) + else: + self.q_bias = None + self.v_bias = None + self.attn_drop = nn.Dropout(attn_drop) + self.proj = nn.Linear(dim, dim) + self.proj_drop = nn.Dropout(proj_drop) + self.softmax = nn.Softmax(axis=-1) + + def forward(self, x, mask=None): + """ + Args: + x: input features with shape of (num_windows*B, N, C) + mask: (0/-inf) mask with shape of (num_windows, Wh*Ww, Wh*Ww) or None + """ + B_, N, C = x.shape + qkv_bias = None + if self.q_bias is not None: + qkv_bias = paddle.concat( + x=[self.q_bias, paddle.zeros_like(self.v_bias), self.v_bias]) + qkv = F.linear(x=x, weight=self.qkv.weight, bias=qkv_bias) + qkv = qkv.reshape(shape=[ + B_, N, 3, self.num_heads, qkv.shape[-1] // (3 * self.num_heads) + ]).transpose(perm=[2, 0, 3, 1, 4]) + q, k, v = qkv[0], qkv[1], qkv[ + 2] # make paddlescript happy (cannot use tensor as tuple) + + # cosine attention + attn = (F.normalize( + q, axis=-1) @F.normalize( + k, axis=-1).transpose(perm=[0, 1, 3, 2])) + logit_scale = paddle.clip( + self.logit_scale, max=math.log(1. / 0.01)).exp() + attn = attn * logit_scale + + relative_position_bias_table = self.cpb_mlp( + self.relative_coords_table).reshape([-1, self.num_heads]) + relative_position_bias = relative_position_bias_table[ + self.relative_position_index.reshape([-1])].reshape([ + self.window_size[0] * self.window_size[1], + self.window_size[0] * self.window_size[1], -1 + ]) # Wh*Ww,Wh*Ww,nH + relative_position_bias = relative_position_bias.transpose( + perm=[2, 0, 1]) # nH, Wh*Ww, Wh*Ww + relative_position_bias = 16 * F.sigmoid(relative_position_bias) + attn = attn + relative_position_bias.unsqueeze(0) + + if mask is not None: + nW = mask.shape[0] + attn = attn.reshape([B_ // nW, nW, self.num_heads, N, N + ]) + mask.unsqueeze(1).unsqueeze(0) + attn = attn.reshape([-1, self.num_heads, N, N]) + attn = self.softmax(attn) + else: + attn = self.softmax(attn) + + attn = self.attn_drop(attn) + + x = (attn @v).transpose(perm=[0, 2, 1, 3]).reshape(shape=[B_, N, C]) + x = self.proj(x) + x = self.proj_drop(x) + return x + + def extra_repr(self): + return f'dim={self.dim}, window_size={self.window_size}, ' \ + f'pretrained_window_size={self.pretrained_window_size}, num_heads={self.num_heads}' + + def flops(self, N): + # calculate flops for 1 window with token length of N + flops = 0 + flops += N * self.dim * 3 * self.dim + flops += self.num_heads * N * (self.dim // self.num_heads) * N + flops += self.num_heads * N * N * (self.dim // self.num_heads) + flops += N * self.dim * self.dim + return flops + + +class SwinTransformerBlock(nn.Layer): + r""" Swin Transformer Block. + + Args: + dim (int): Number of input channels. + input_resolution (tuple[int]): Input resulotion. + num_heads (int): Number of attention heads. + window_size (int): Window size. + shift_size (int): Shift size for SW-MSA. + mlp_ratio (float): Ratio of mlp hidden dim to embedding dim. + qkv_bias (bool, optional): If True, add a learnable bias to query, key, value. Default: True + drop (float, optional): Dropout rate. Default: 0.0 + attn_drop (float, optional): Attention dropout rate. Default: 0.0 + drop_path (float, optional): Stochastic depth rate. Default: 0.0 + act_layer (nn.Module, optional): Activation layer. Default: nn.GELU + norm_layer (nn.Module, optional): Normalization layer. Default: nn.LayerNorm + pretrained_window_size (int): Window size in pre-training. + """ + + def __init__(self, + dim, + input_resolution, + num_heads, + window_size=8, + shift_size=0, + mlp_ratio=4., + qkv_bias=True, + drop=0., + attn_drop=0., + drop_path=0., + act_layer=nn.GELU, + norm_layer=nn.LayerNorm, + pretrained_window_size=0): + super().__init__() + self.dim = dim + self.input_resolution = input_resolution + self.num_heads = num_heads + self.window_size = window_size + self.shift_size = shift_size + self.mlp_ratio = mlp_ratio + if min(self.input_resolution) <= self.window_size: + # if window size is larger than input resolution, we don't partition windows + self.shift_size = 0 + self.window_size = min(self.input_resolution) + assert 0 <= self.shift_size < self.window_size, "shift_size must in 0-window_size" + + self.norm1 = norm_layer(dim) + self.attn = WindowAttention( + dim, + window_size=to_2tuple(self.window_size), + num_heads=num_heads, + qkv_bias=qkv_bias, + attn_drop=attn_drop, + proj_drop=drop, + pretrained_window_size=to_2tuple(pretrained_window_size)) + + self.drop_path = DropPath( + drop_path) if drop_path > 0. else nn.Identity() + self.norm2 = norm_layer(dim) + mlp_hidden_dim = int(dim * mlp_ratio) + self.mlp = Mlp(in_features=dim, + hidden_features=mlp_hidden_dim, + act_layer=act_layer, + drop=drop) + + if self.shift_size > 0: + # calculate attention mask for SW-MSA + H, W = self.input_resolution + img_mask = paddle.zeros([1, H, W, 1]) # 1 H W 1 + h_slices = (slice(0, -self.window_size), + slice(-self.window_size, -self.shift_size), + slice(-self.shift_size, None)) + w_slices = (slice(0, -self.window_size), + slice(-self.window_size, -self.shift_size), + slice(-self.shift_size, None)) + cnt = 0 + for h in h_slices: + for w in w_slices: + img_mask[:, h, w, :] = cnt + cnt += 1 + + mask_windows = window_partition( + img_mask, self.window_size) # nW, window_size, window_size, 1 + mask_windows = mask_windows.reshape( + shape=[-1, self.window_size * self.window_size]) + attn_mask = mask_windows.unsqueeze(1) - mask_windows.unsqueeze(2) + attn_mask = masked_fill(attn_mask, attn_mask != 0, float(-100.0)) + attn_mask = masked_fill(attn_mask, attn_mask == 0, float(0.0)) + else: + attn_mask = None + + self.register_buffer("attn_mask", attn_mask) + + def forward(self, x): + H, W = self.input_resolution + B, L, C = x.shape + assert L == H * W, "input feature has wrong size" + + shortcut = x + x = x.reshape(shape=[B, H, W, C]) + + # cyclic shift + if self.shift_size > 0: + shifted_x = paddle.roll( + x, shifts=(-self.shift_size, -self.shift_size), axis=(1, 2)) + else: + shifted_x = x + + # partition windows + x_windows = window_partition( + shifted_x, self.window_size) # nW*B, window_size, window_size, C + x_windows = x_windows.reshape( + [-1, self.window_size * self.window_size, + C]) # nW*B, window_size*window_size, C + + # W-MSA/SW-MSA + attn_windows = self.attn( + x_windows, mask=self.attn_mask) # nW*B, window_size*window_size, C + + # merge windows + attn_windows = attn_windows.reshape( + [-1, self.window_size, self.window_size, C]) + shifted_x = window_reverse(attn_windows, self.window_size, H, + W) # B H' W' C + + # reverse cyclic shift + if self.shift_size > 0: + x = paddle.roll( + shifted_x, + shifts=(self.shift_size, self.shift_size), + axis=(1, 2)) + else: + x = shifted_x + x = x.reshape([B, H * W, C]) + x = shortcut + self.drop_path(self.norm1(x)) + + # FFN + x = x + self.drop_path(self.norm2(self.mlp(x))) + + return x + + def extra_repr(self): + return f"dim={self.dim}, input_resolution={self.input_resolution}, num_heads={self.num_heads}, " \ + f"window_size={self.window_size}, shift_size={self.shift_size}, mlp_ratio={self.mlp_ratio}" + + def flops(self): + flops = 0 + H, W = self.input_resolution + # norm1 + flops += self.dim * H * W + # W-MSA/SW-MSA + nW = H * W / self.window_size / self.window_size + flops += nW * self.attn.flops(self.window_size * self.window_size) + # mlp + flops += 2 * H * W * self.dim * self.dim * self.mlp_ratio + # norm2 + flops += self.dim * H * W + return flops + + +class PatchMerging(nn.Layer): + r""" Patch Merging Layer. + + Args: + input_resolution (tuple[int]): Resolution of input feature. + dim (int): Number of input channels. + norm_layer (nn.Module, optional): Normalization layer. Default: nn.LayerNorm + """ + + def __init__(self, input_resolution, dim, norm_layer=nn.LayerNorm): + super().__init__() + self.input_resolution = input_resolution + self.dim = dim + self.reduction = nn.Linear(4 * dim, 2 * dim, bias_attr=False) + self.norm = norm_layer(2 * dim) + + def forward(self, x): + """ + x: B, H*W, C + """ + H, W = self.input_resolution + B, L, C = x.shape + assert L == H * W, "input feature has wrong size" + assert H % 2 == 0 and W % 2 == 0, f"x size ({H}*{W}) are not even." + + x = x.reshape([B, H // 2, 2, W // 2, 2, C]) + x = x.transpose((0, 1, 3, 4, 2, 5)) + x = x.reshape([B, H * W // 4, 4 * C]) # B H/2*W/2 4*C + x = self.reduction(x) + x = self.norm(x) + return x + + def extra_repr(self): + return f"input_resolution={self.input_resolution}, dim={self.dim}" + + def flops(self): + H, W = self.input_resolution + flops = (H // 2) * (W // 2) * 4 * self.dim * 2 * self.dim + flops += H * W * self.dim // 2 + return flops + + +class BasicLayer(nn.Layer): + """ A basic Swin Transformer layer for one stage. + + Args: + dim (int): Number of input channels. + input_resolution (tuple[int]): Input resolution. + depth (int): Number of blocks. + num_heads (int): Number of attention heads. + window_size (int): Local window size. + mlp_ratio (float): Ratio of mlp hidden dim to embedding dim. + qkv_bias (bool, optional): If True, add a learnable bias to query, key, value. Default: True + drop (float, optional): Dropout rate. Default: 0.0 + attn_drop (float, optional): Attention dropout rate. Default: 0.0 + drop_path (float | tuple[float], optional): Stochastic depth rate. Default: 0.0 + norm_layer (nn.Module, optional): Normalization layer. Default: nn.LayerNorm + downsample (nn.Module | None, optional): Downsample layer at the end of the layer. Default: None + pretrained_window_size (int): Local window size in pre-training. + """ + + def __init__(self, + dim, + input_resolution, + depth, + num_heads, + window_size, + mlp_ratio=4., + qkv_bias=True, + drop=0., + attn_drop=0., + drop_path=0., + norm_layer=nn.LayerNorm, + downsample=None, + pretrained_window_size=0): + + super().__init__() + self.dim = dim + self.input_resolution = input_resolution + self.depth = depth + + # build blocks + self.blocks = nn.LayerList([ + SwinTransformerBlock( + dim=dim, + input_resolution=input_resolution, + num_heads=num_heads, + window_size=window_size, + shift_size=0 if (i % 2 == 0) else window_size // 2, + mlp_ratio=mlp_ratio, + qkv_bias=qkv_bias, + drop=drop, + attn_drop=attn_drop, + drop_path=drop_path[i] + if isinstance(drop_path, list) else drop_path, + norm_layer=norm_layer, + pretrained_window_size=pretrained_window_size) + for i in range(depth) + ]) + + # patch merging layer + if downsample is not None: + self.downsample = downsample( + input_resolution, dim=dim, norm_layer=norm_layer) + else: + self.downsample = None + + def forward(self, x): + for blk in self.blocks: + x = blk(x) + if self.downsample is not None: + x = self.downsample(x) + return x + + def extra_repr(self): + return f"dim={self.dim}, input_resolution={self.input_resolution}, depth={self.depth}" + + def flops(self): + flops = 0 + for blk in self.blocks: + flops += blk.flops() + if self.downsample is not None: + flops += self.downsample.flops() + return flops + + +class PatchEmbed(nn.Layer): + r""" Image to Patch Embedding + + Args: + img_size (int): Image size. Default: 256. + patch_size (int): Patch token size. Default: 4. + in_chans (int): Number of input image channels. Default: 3. + embed_dim (int): Number of linear projection output channels. Default: 96. + norm_layer (nn.Module, optional): Normalization layer. Default: None + """ + + def __init__(self, + img_size=256, + patch_size=4, + in_chans=3, + embed_dim=96, + norm_layer=None): + super().__init__() + img_size = to_2tuple(img_size) + patch_size = to_2tuple(patch_size) + patches_resolution = [ + img_size[0] // patch_size[0], img_size[1] // patch_size[1] + ] + self.img_size = img_size + self.patch_size = patch_size + self.patches_resolution = patches_resolution + self.num_patches = patches_resolution[0] * patches_resolution[1] + + self.in_chans = in_chans + self.embed_dim = embed_dim + + self.proj = nn.Conv2D( + in_chans, embed_dim, kernel_size=patch_size, stride=patch_size) + if norm_layer is not None: + self.norm = norm_layer(embed_dim) + else: + self.norm = None + + def forward(self, x): + B, C, H, W = x.shape + # FIXME look at relaxing size constraints + assert H == self.img_size[0] and W == self.img_size[1], \ + f"Input image size ({H}*{W}) doesn't match model ({self.img_size[0]}*{self.img_size[1]})." + x = self.proj(x).flatten(2).transpose([0, 2, 1]) # B Ph*Pw C + if self.norm is not None: + x = self.norm(x) + return x + + def flops(self): + Ho, Wo = self.patches_resolution + flops = Ho * Wo * self.embed_dim * self.in_chans * ( + self.patch_size[0] * self.patch_size[1]) + if self.norm is not None: + flops += Ho * Wo * self.embed_dim + return flops + + +class SwinTransformerV2(nn.Layer): + r""" Swin TransformerV2 + A PaddlePaddle impl of : `Swin Transformer V2: Scaling Up Capacity and Resolution` - + https://arxiv.org/abs/2111.09883 + + Args: + img_size (int | tuple(int)): Input image size. Default 256 + patch_size (int | tuple(int)): Patch size. Default: 4 + in_chans (int): Number of input image channels. Default: 3 + class_num (int): Number of classes for classification head. Default: 1000 + embed_dim (int): Patch embedding dimension. Default: 96 + depths (tuple(int)): Depth of each Swin Transformer layer. + num_heads (tuple(int)): Number of attention heads in different layers. + window_size (int): Window size. Default: 7 + mlp_ratio (float): Ratio of mlp hidden dim to embedding dim. Default: 4 + qkv_bias (bool): If True, add a learnable bias to query, key, value. Default: True + drop_rate (float): Dropout rate. Default: 0 + attn_drop_rate (float): Attention dropout rate. Default: 0 + drop_path_rate (float): Stochastic depth rate. Default: 0.1 + norm_layer (nn.Layer): Normalization layer. Default: nn.LayerNorm. + ape (bool): If True, add absolute position embedding to the patch embedding. Default: False + patch_norm (bool): If True, add normalization after patch embedding. Default: True + pretrained_window_sizes (tuple(int)): Pretrained window sizes of each layer. + """ + + def __init__(self, + img_size=256, + patch_size=4, + in_chans=3, + class_num=1000, + embed_dim=96, + depths=[2, 2, 6, 2], + num_heads=[3, 6, 12, 24], + window_size=7, + mlp_ratio=4., + qkv_bias=True, + drop_rate=0., + attn_drop_rate=0., + drop_path_rate=0.1, + norm_layer=nn.LayerNorm, + ape=False, + patch_norm=True, + pretrained_window_sizes=[0, 0, 0, 0], + **kwargs): + super().__init__() + + self.class_num = class_num + self.num_layers = len(depths) + self.embed_dim = embed_dim + self.ape = ape + self.patch_norm = patch_norm + self.num_features = int(embed_dim * 2**(self.num_layers - 1)) + self.mlp_ratio = mlp_ratio + + # split image into non-overlapping patches + self.patch_embed = PatchEmbed( + img_size=img_size, + patch_size=patch_size, + in_chans=in_chans, + embed_dim=embed_dim, + norm_layer=norm_layer if self.patch_norm else None) + num_patches = self.patch_embed.num_patches + patches_resolution = self.patch_embed.patches_resolution + self.patches_resolution = patches_resolution + + # absolute position embedding + if self.ape: + self.absolute_pos_embed = self.create_parameter( + shape=(1, num_patches, embed_dim), default_initializer=zeros_) + trunc_normal_(self.absolute_pos_embed) + + self.pos_drop = nn.Dropout(p=drop_rate) + + # stochastic depth + dpr = [ + x.item() for x in paddle.linspace(0, drop_path_rate, sum(depths)) + ] # stochastic depth decay rule + + # build layers + self.layers = nn.LayerList() + for i_layer in range(self.num_layers): + layer = BasicLayer( + dim=int(embed_dim * 2**i_layer), + input_resolution=(patches_resolution[0] // (2**i_layer), + patches_resolution[1] // (2**i_layer)), + depth=depths[i_layer], + num_heads=num_heads[i_layer], + window_size=window_size, + mlp_ratio=self.mlp_ratio, + qkv_bias=qkv_bias, + drop=drop_rate, + attn_drop=attn_drop_rate, + drop_path=dpr[sum(depths[:i_layer]):sum(depths[:i_layer + 1])], + norm_layer=norm_layer, + downsample=PatchMerging + if (i_layer < self.num_layers - 1) else None, + pretrained_window_size=pretrained_window_sizes[i_layer]) + self.layers.append(layer) + + self.norm = norm_layer(self.num_features) + self.avgpool = nn.AdaptiveAvgPool1D(1) + self.head = nn.Linear(self.num_features, + class_num) if class_num > 0 else nn.Identity() + + self.apply(self._init_weights) + + def _init_weights(self, m): + if isinstance(m, nn.Linear): + trunc_normal_(m.weight) + if isinstance(m, nn.Linear) and m.bias is not None: + zeros_(m.bias) + elif isinstance(m, nn.LayerNorm): + zeros_(m.bias) + ones_(m.weight) + + def forward_features(self, x): + x = self.patch_embed(x) + if self.ape: + x = x + self.absolute_pos_embed + x = self.pos_drop(x) + + for layer in self.layers: + x = layer(x) + + x = self.norm(x) # B L C + x = self.avgpool(x.transpose([0, 2, 1])) # B C 1 + x = paddle.flatten(x, 1) + return x + + def forward(self, x): + x = self.forward_features(x) + x = self.head(x) + return x + + def flops(self): + flops = 0 + flops += self.patch_embed.flops() + for i, layer in enumerate(self.layers): + flops += layer.flops() + flops += self.num_features * self.patches_resolution[ + 0] * self.patches_resolution[1] // (2**self.num_layers) + flops += self.num_features * self.class_num + return flops + + +def _load_pretrained(pretrained, + model, + model_url, + use_ssld=False, + use_imagenet22k_pretrained=False, + use_imagenet22kto1k_pretrained=False): + if pretrained is False: + pass + elif pretrained is True: + load_dygraph_pretrain_from_url( + model, + model_url, + use_ssld=use_ssld, + use_imagenet22k_pretrained=False, + use_imagenet22kto1k_pretrained=False) + elif isinstance(pretrained, str): + load_dygraph_pretrain(model, pretrained, **kwargs) + else: + raise RuntimeError( + "pretrained type is not available. Please use `string` or `boolean` type." + ) + + +def SwinTransformerV2_tiny_patch4_window8_256(pretrained=False, + use_ssld=False, + **kwargs): + model = SwinTransformerV2( + img_size=256, + embed_dim=96, + depths=[2, 2, 6, 2], + num_heads=[3, 6, 12, 24], + window_size=8, + drop_path_rate=0.2, + **kwargs) + _load_pretrained( + pretrained, + model, + MODEL_URLS["SwinTransformerV2_tiny_patch4_window8_256"], + use_ssld=use_ssld) + return model + + +def SwinTransformerV2_tiny_patch4_window16_256(pretrained=False, + use_ssld=False, + **kwargs): + model = SwinTransformerV2( + img_size=256, + embed_dim=96, + depths=[2, 2, 6, 2], + num_heads=[3, 6, 12, 24], + window_size=16, + drop_path_rate=0.2, + **kwargs) + _load_pretrained( + pretrained, + model, + MODEL_URLS["SwinTransformerV2_tiny_patch4_window16_256"], + use_ssld=use_ssld) + return model + + +def SwinTransformerV2_small_patch4_window8_256(pretrained=False, + use_ssld=False, + **kwargs): + model = SwinTransformerV2( + img_size=256, + embed_dim=96, + depths=[2, 2, 18, 2], + num_heads=[3, 6, 12, 24], + window_size=8, + drop_path_rate=0.3, + **kwargs) + _load_pretrained( + pretrained, + model, + MODEL_URLS["SwinTransformerV2_small_patch4_window8_256"], + use_ssld=use_ssld) + return model + + +def SwinTransformerV2_small_patch4_window16_256(pretrained=False, + use_ssld=False, + **kwargs): + model = SwinTransformerV2( + img_size=256, + embed_dim=96, + depths=[2, 2, 18, 2], + num_heads=[3, 6, 12, 24], + window_size=16, + drop_path_rate=0.3, + **kwargs) + _load_pretrained( + pretrained, + model, + MODEL_URLS["SwinTransformerV2_small_patch4_window16_256"], + use_ssld=use_ssld) + return model + + +def SwinTransformerV2_base_patch4_window8_256(pretrained=False, + use_ssld=False, + **kwargs): + model = SwinTransformerV2( + img_size=256, + embed_dim=128, + depths=[2, 2, 18, 2], + num_heads=[4, 8, 16, 32], + window_size=8, + drop_path_rate=0.5, + **kwargs) + _load_pretrained( + pretrained, + model, + MODEL_URLS["SwinTransformerV2_base_patch4_window8_256"], + use_ssld=use_ssld, + use_imagenet22k_pretrained=use_imagenet22k_pretrained) + return model + + +def SwinTransformerV2_base_patch4_window16_256( + pretrained=False, + use_ssld=False, + use_imagenet22k_pretrained=False, + use_imagenet22kto1k_pretrained=False, + **kwargs): + model = SwinTransformerV2( + img_size=256, + embed_dim=128, + depths=[2, 2, 18, 2], + num_heads=[4, 8, 16, 32], + window_size=16, + drop_path_rate=0.5, # if use imagenet22k or imagenet22kto1k, drop_path_rate=0.2 + **kwargs + ) # if use imagenet22k, set pretrained_window_sizes=[12, 12, 12, 6] + _load_pretrained( + pretrained, + model, + MODEL_URLS["SwinTransformerV2_base_patch4_window16_256"], + use_ssld=use_ssld, + use_imagenet22k_pretrained=use_imagenet22k_pretrained, + use_imagenet22kto1k_pretrained=use_imagenet22kto1k_pretrained) + return model + + +def SwinTransformerV2_base_patch4_window24_384( + pretrained=False, + use_ssld=False, + use_imagenet22k_pretrained=False, + use_imagenet22kto1k_pretrained=False, + **kwargs): + model = SwinTransformerV2( + img_size=384, + embed_dim=128, + depths=[2, 2, 18, 2], + num_heads=[4, 8, 16, 32], + window_size=24, + drop_path_rate=0.2, + pretrained_window_sizes=[12, 12, 12, 6], + **kwargs) + _load_pretrained( + pretrained, + model, + MODEL_URLS["SwinTransformerV2_base_patch4_window24_384"], + use_ssld=use_ssld, + use_imagenet22k_pretrained=use_imagenet22k_pretrained, + use_imagenet22kto1k_pretrained=use_imagenet22kto1k_pretrained) + return model + + +def SwinTransformerV2_large_patch4_window16_256( + pretrained=False, + use_ssld=False, + use_imagenet22k_pretrained=False, + use_imagenet22kto1k_pretrained=False, + **kwargs): + model = SwinTransformerV2( + img_size=256, + embed_dim=192, + depths=[2, 2, 18, 2], + num_heads=[6, 12, 24, 48], + window_size=16, + drop_path_rate=0.2, + pretrained_window_sizes=[12, 12, 12, 6], + **kwargs) + _load_pretrained( + pretrained, + model, + MODEL_URLS["SwinTransformerV2_large_patch4_window16_256"], + use_ssld=use_ssld, + use_imagenet22k_pretrained=use_imagenet22k_pretrained, + use_imagenet22kto1k_pretrained=use_imagenet22kto1k_pretrained) + return model + + +def SwinTransformerV2_large_patch4_window24_384( + pretrained=False, + use_ssld=False, + use_imagenet22k_pretrained=False, + use_imagenet22kto1k_pretrained=False, + **kwargs): + model = SwinTransformerV2( + img_size=384, + embed_dim=192, + depths=[2, 2, 18, 2], + num_heads=[6, 12, 24, 48], + window_size=24, + drop_path_rate=0.2, + pretrained_window_sizes=[12, 12, 12, 6], + **kwargs) + _load_pretrained( + pretrained, + model, + MODEL_URLS["SwinTransformerV2_large_patch4_window24_384"], + use_ssld=use_ssld, + use_imagenet22k_pretrained=use_imagenet22k_pretrained, + use_imagenet22kto1k_pretrained=use_imagenet22kto1k_pretrained) + return model