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			1017 lines
		
	
	
		
			45 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			1017 lines
		
	
	
		
			45 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| # -----------------------------------------------------------------------------------
 | |
| # Swin2SR: Swin2SR: SwinV2 Transformer for Compressed Image Super-Resolution and Restoration, https://arxiv.org/abs/
 | |
| # Written by Conde and Choi et al.
 | |
| # -----------------------------------------------------------------------------------
 | |
| 
 | |
| import math
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| import numpy as np
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| import torch
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| import torch.nn as nn
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| import torch.nn.functional as F
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| import torch.utils.checkpoint as checkpoint
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| from timm.models.layers import DropPath, to_2tuple, trunc_normal_
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| 
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| 
 | |
| class Mlp(nn.Module):
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|     def __init__(self, in_features, hidden_features=None, out_features=None, act_layer=nn.GELU, drop=0.):
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|         super().__init__()
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|         out_features = out_features or in_features
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|         hidden_features = hidden_features or in_features
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|         self.fc1 = nn.Linear(in_features, hidden_features)
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|         self.act = act_layer()
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|         self.fc2 = nn.Linear(hidden_features, out_features)
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|         self.drop = nn.Dropout(drop)
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| 
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|     def forward(self, x):
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|         x = self.fc1(x)
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|         x = self.act(x)
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|         x = self.drop(x)
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|         x = self.fc2(x)
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|         x = self.drop(x)
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|         return x
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| 
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| 
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| def window_partition(x, window_size):
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|     """
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|     Args:
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|         x: (B, H, W, C)
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|         window_size (int): window size
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|     Returns:
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|         windows: (num_windows*B, window_size, window_size, C)
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|     """
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|     B, H, W, C = x.shape
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|     x = x.view(B, H // window_size, window_size, W // window_size, window_size, C)
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|     windows = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(-1, window_size, window_size, C)
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|     return windows
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| 
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| 
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| def window_reverse(windows, window_size, H, W):
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|     """
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|     Args:
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|         windows: (num_windows*B, window_size, window_size, C)
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|         window_size (int): Window size
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|         H (int): Height of image
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|         W (int): Width of image
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|     Returns:
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|         x: (B, H, W, C)
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|     """
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|     B = int(windows.shape[0] / (H * W / window_size / window_size))
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|     x = windows.view(B, H // window_size, W // window_size, window_size, window_size, -1)
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|     x = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(B, H, W, -1)
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|     return x
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| 
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| class WindowAttention(nn.Module):
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|     r""" Window based multi-head self attention (W-MSA) module with relative position bias.
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|     It supports both of shifted and non-shifted window.
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|     Args:
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|         dim (int): Number of input channels.
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|         window_size (tuple[int]): The height and width of the window.
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|         num_heads (int): Number of attention heads.
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|         qkv_bias (bool, optional):  If True, add a learnable bias to query, key, value. Default: True
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|         attn_drop (float, optional): Dropout ratio of attention weight. Default: 0.0
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|         proj_drop (float, optional): Dropout ratio of output. Default: 0.0
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|         pretrained_window_size (tuple[int]): The height and width of the window in pre-training.
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|     """
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| 
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|     def __init__(self, dim, window_size, num_heads, qkv_bias=True, attn_drop=0., proj_drop=0.,
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|                  pretrained_window_size=[0, 0]):
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| 
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|         super().__init__()
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|         self.dim = dim
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|         self.window_size = window_size  # Wh, Ww
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|         self.pretrained_window_size = pretrained_window_size
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|         self.num_heads = num_heads
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| 
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|         self.logit_scale = nn.Parameter(torch.log(10 * torch.ones((num_heads, 1, 1))), requires_grad=True)
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| 
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|         # mlp to generate continuous relative position bias
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|         self.cpb_mlp = nn.Sequential(nn.Linear(2, 512, bias=True),
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|                                      nn.ReLU(inplace=True),
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|                                      nn.Linear(512, num_heads, bias=False))
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| 
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|         # get relative_coords_table
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|         relative_coords_h = torch.arange(-(self.window_size[0] - 1), self.window_size[0], dtype=torch.float32)
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|         relative_coords_w = torch.arange(-(self.window_size[1] - 1), self.window_size[1], dtype=torch.float32)
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|         relative_coords_table = torch.stack(
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|             torch.meshgrid([relative_coords_h,
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|                             relative_coords_w])).permute(1, 2, 0).contiguous().unsqueeze(0)  # 1, 2*Wh-1, 2*Ww-1, 2
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|         if pretrained_window_size[0] > 0:
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|             relative_coords_table[:, :, :, 0] /= (pretrained_window_size[0] - 1)
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|             relative_coords_table[:, :, :, 1] /= (pretrained_window_size[1] - 1)
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|         else:
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|             relative_coords_table[:, :, :, 0] /= (self.window_size[0] - 1)
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|             relative_coords_table[:, :, :, 1] /= (self.window_size[1] - 1)
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|         relative_coords_table *= 8  # normalize to -8, 8
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|         relative_coords_table = torch.sign(relative_coords_table) * torch.log2(
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|             torch.abs(relative_coords_table) + 1.0) / np.log2(8)
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| 
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|         self.register_buffer("relative_coords_table", relative_coords_table)
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| 
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|         # get pair-wise relative position index for each token inside the window
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|         coords_h = torch.arange(self.window_size[0])
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|         coords_w = torch.arange(self.window_size[1])
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|         coords = torch.stack(torch.meshgrid([coords_h, coords_w]))  # 2, Wh, Ww
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|         coords_flatten = torch.flatten(coords, 1)  # 2, Wh*Ww
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|         relative_coords = coords_flatten[:, :, None] - coords_flatten[:, None, :]  # 2, Wh*Ww, Wh*Ww
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|         relative_coords = relative_coords.permute(1, 2, 0).contiguous()  # Wh*Ww, Wh*Ww, 2
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|         relative_coords[:, :, 0] += self.window_size[0] - 1  # shift to start from 0
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|         relative_coords[:, :, 1] += self.window_size[1] - 1
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|         relative_coords[:, :, 0] *= 2 * self.window_size[1] - 1
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|         relative_position_index = relative_coords.sum(-1)  # Wh*Ww, Wh*Ww
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|         self.register_buffer("relative_position_index", relative_position_index)
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| 
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|         self.qkv = nn.Linear(dim, dim * 3, bias=False)
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|         if qkv_bias:
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|             self.q_bias = nn.Parameter(torch.zeros(dim))
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|             self.v_bias = nn.Parameter(torch.zeros(dim))
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|         else:
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|             self.q_bias = None
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|             self.v_bias = None
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|         self.attn_drop = nn.Dropout(attn_drop)
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|         self.proj = nn.Linear(dim, dim)
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|         self.proj_drop = nn.Dropout(proj_drop)
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|         self.softmax = nn.Softmax(dim=-1)
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| 
 | |
|     def forward(self, x, mask=None):
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|         """
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|         Args:
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|             x: input features with shape of (num_windows*B, N, C)
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|             mask: (0/-inf) mask with shape of (num_windows, Wh*Ww, Wh*Ww) or None
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|         """
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|         B_, N, C = x.shape
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|         qkv_bias = None
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|         if self.q_bias is not None:
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|             qkv_bias = torch.cat((self.q_bias, torch.zeros_like(self.v_bias, requires_grad=False), self.v_bias))
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|         qkv = F.linear(input=x, weight=self.qkv.weight, bias=qkv_bias)
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|         qkv = qkv.reshape(B_, N, 3, self.num_heads, -1).permute(2, 0, 3, 1, 4)
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|         q, k, v = qkv[0], qkv[1], qkv[2]  # make torchscript happy (cannot use tensor as tuple)
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| 
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|         # cosine attention
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|         attn = (F.normalize(q, dim=-1) @ F.normalize(k, dim=-1).transpose(-2, -1))
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|         logit_scale = torch.clamp(self.logit_scale, max=torch.log(torch.tensor(1. / 0.01)).to(self.logit_scale.device)).exp()
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|         attn = attn * logit_scale
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| 
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|         relative_position_bias_table = self.cpb_mlp(self.relative_coords_table).view(-1, self.num_heads)
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|         relative_position_bias = relative_position_bias_table[self.relative_position_index.view(-1)].view(
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|             self.window_size[0] * self.window_size[1], self.window_size[0] * self.window_size[1], -1)  # Wh*Ww,Wh*Ww,nH
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|         relative_position_bias = relative_position_bias.permute(2, 0, 1).contiguous()  # nH, Wh*Ww, Wh*Ww
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|         relative_position_bias = 16 * torch.sigmoid(relative_position_bias)
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|         attn = attn + relative_position_bias.unsqueeze(0)
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| 
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|         if mask is not None:
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|             nW = mask.shape[0]
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|             attn = attn.view(B_ // nW, nW, self.num_heads, N, N) + mask.unsqueeze(1).unsqueeze(0)
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|             attn = attn.view(-1, self.num_heads, N, N)
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|             attn = self.softmax(attn)
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|         else:
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|             attn = self.softmax(attn)
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| 
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|         attn = self.attn_drop(attn)
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| 
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|         x = (attn @ v).transpose(1, 2).reshape(B_, N, C)
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|         x = self.proj(x)
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|         x = self.proj_drop(x)
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|         return x
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| 
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|     def extra_repr(self) -> str:
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|         return f'dim={self.dim}, window_size={self.window_size}, ' \
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|                f'pretrained_window_size={self.pretrained_window_size}, num_heads={self.num_heads}'
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| 
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|     def flops(self, N):
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|         # calculate flops for 1 window with token length of N
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|         flops = 0
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|         # qkv = self.qkv(x)
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|         flops += N * self.dim * 3 * self.dim
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|         # attn = (q @ k.transpose(-2, -1))
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|         flops += self.num_heads * N * (self.dim // self.num_heads) * N
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|         #  x = (attn @ v)
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|         flops += self.num_heads * N * N * (self.dim // self.num_heads)
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|         # x = self.proj(x)
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|         flops += N * self.dim * self.dim
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|         return flops
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| 
 | |
| class SwinTransformerBlock(nn.Module):
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|     r""" Swin Transformer Block.
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|     Args:
 | |
|         dim (int): Number of input channels.
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|         input_resolution (tuple[int]): Input resulotion.
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|         num_heads (int): Number of attention heads.
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|         window_size (int): Window size.
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|         shift_size (int): Shift size for SW-MSA.
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|         mlp_ratio (float): Ratio of mlp hidden dim to embedding dim.
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|         qkv_bias (bool, optional): If True, add a learnable bias to query, key, value. Default: True
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|         drop (float, optional): Dropout rate. Default: 0.0
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|         attn_drop (float, optional): Attention dropout rate. Default: 0.0
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|         drop_path (float, optional): Stochastic depth rate. Default: 0.0
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|         act_layer (nn.Module, optional): Activation layer. Default: nn.GELU
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|         norm_layer (nn.Module, optional): Normalization layer.  Default: nn.LayerNorm
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|         pretrained_window_size (int): Window size in pre-training.
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|     """
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| 
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|     def __init__(self, dim, input_resolution, num_heads, window_size=7, shift_size=0,
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|                  mlp_ratio=4., qkv_bias=True, drop=0., attn_drop=0., drop_path=0.,
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|                  act_layer=nn.GELU, norm_layer=nn.LayerNorm, pretrained_window_size=0):
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|         super().__init__()
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|         self.dim = dim
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|         self.input_resolution = input_resolution
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|         self.num_heads = num_heads
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|         self.window_size = window_size
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|         self.shift_size = shift_size
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|         self.mlp_ratio = mlp_ratio
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|         if min(self.input_resolution) <= self.window_size:
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|             # if window size is larger than input resolution, we don't partition windows
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|             self.shift_size = 0
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|             self.window_size = min(self.input_resolution)
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|         assert 0 <= self.shift_size < self.window_size, "shift_size must in 0-window_size"
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| 
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|         self.norm1 = norm_layer(dim)
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|         self.attn = WindowAttention(
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|             dim, window_size=to_2tuple(self.window_size), num_heads=num_heads,
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|             qkv_bias=qkv_bias, attn_drop=attn_drop, proj_drop=drop,
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|             pretrained_window_size=to_2tuple(pretrained_window_size))
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| 
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|         self.drop_path = DropPath(drop_path) if drop_path > 0. else nn.Identity()
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|         self.norm2 = norm_layer(dim)
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|         mlp_hidden_dim = int(dim * mlp_ratio)
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|         self.mlp = Mlp(in_features=dim, hidden_features=mlp_hidden_dim, act_layer=act_layer, drop=drop)
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| 
 | |
|         if self.shift_size > 0:
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|             attn_mask = self.calculate_mask(self.input_resolution)
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|         else:
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|             attn_mask = None
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| 
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|         self.register_buffer("attn_mask", attn_mask)
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|         
 | |
|     def calculate_mask(self, x_size):
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|         # calculate attention mask for SW-MSA
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|         H, W = x_size
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|         img_mask = torch.zeros((1, H, W, 1))  # 1 H W 1
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|         h_slices = (slice(0, -self.window_size),
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|                     slice(-self.window_size, -self.shift_size),
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|                     slice(-self.shift_size, None))
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|         w_slices = (slice(0, -self.window_size),
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|                     slice(-self.window_size, -self.shift_size),
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|                     slice(-self.shift_size, None))
 | |
|         cnt = 0
 | |
|         for h in h_slices:
 | |
|             for w in w_slices:
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|                 img_mask[:, h, w, :] = cnt
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|                 cnt += 1
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| 
 | |
|         mask_windows = window_partition(img_mask, self.window_size)  # nW, window_size, window_size, 1
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|         mask_windows = mask_windows.view(-1, self.window_size * self.window_size)
 | |
|         attn_mask = mask_windows.unsqueeze(1) - mask_windows.unsqueeze(2)
 | |
|         attn_mask = attn_mask.masked_fill(attn_mask != 0, float(-100.0)).masked_fill(attn_mask == 0, float(0.0))
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| 
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|         return attn_mask        
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| 
 | |
|     def forward(self, x, x_size):
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|         H, W = x_size
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|         B, L, C = x.shape
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|         #assert L == H * W, "input feature has wrong size"
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| 
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|         shortcut = x
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|         x = x.view(B, H, W, C)
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| 
 | |
|         # cyclic shift
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|         if self.shift_size > 0:
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|             shifted_x = torch.roll(x, shifts=(-self.shift_size, -self.shift_size), dims=(1, 2))
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|         else:
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|             shifted_x = x
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| 
 | |
|         # partition windows
 | |
|         x_windows = window_partition(shifted_x, self.window_size)  # nW*B, window_size, window_size, C
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|         x_windows = x_windows.view(-1, self.window_size * self.window_size, C)  # nW*B, window_size*window_size, C
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| 
 | |
|         # W-MSA/SW-MSA (to be compatible for testing on images whose shapes are the multiple of window size
 | |
|         if self.input_resolution == x_size:
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|             attn_windows = self.attn(x_windows, mask=self.attn_mask)  # nW*B, window_size*window_size, C
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|         else:
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|             attn_windows = self.attn(x_windows, mask=self.calculate_mask(x_size).to(x.device))
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|             
 | |
|         # merge windows
 | |
|         attn_windows = attn_windows.view(-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 = torch.roll(shifted_x, shifts=(self.shift_size, self.shift_size), dims=(1, 2))
 | |
|         else:
 | |
|             x = shifted_x
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|         x = x.view(B, H * W, C)
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|         x = shortcut + self.drop_path(self.norm1(x))
 | |
| 
 | |
|         # FFN
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|         x = x + self.drop_path(self.norm2(self.mlp(x)))
 | |
| 
 | |
|         return x
 | |
| 
 | |
|     def extra_repr(self) -> str:
 | |
|         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.Module):
 | |
|     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=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.view(B, H, W, C)
 | |
| 
 | |
|         x0 = x[:, 0::2, 0::2, :]  # B H/2 W/2 C
 | |
|         x1 = x[:, 1::2, 0::2, :]  # B H/2 W/2 C
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|         x2 = x[:, 0::2, 1::2, :]  # B H/2 W/2 C
 | |
|         x3 = x[:, 1::2, 1::2, :]  # B H/2 W/2 C
 | |
|         x = torch.cat([x0, x1, x2, x3], -1)  # B H/2 W/2 4*C
 | |
|         x = x.view(B, -1, 4 * C)  # B H/2*W/2 4*C
 | |
| 
 | |
|         x = self.reduction(x)
 | |
|         x = self.norm(x)
 | |
| 
 | |
|         return x
 | |
| 
 | |
|     def extra_repr(self) -> str:
 | |
|         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.Module):
 | |
|     """ 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
 | |
|         use_checkpoint (bool): Whether to use checkpointing to save memory. Default: False.
 | |
|         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, use_checkpoint=False,
 | |
|                  pretrained_window_size=0):
 | |
| 
 | |
|         super().__init__()
 | |
|         self.dim = dim
 | |
|         self.input_resolution = input_resolution
 | |
|         self.depth = depth
 | |
|         self.use_checkpoint = use_checkpoint
 | |
| 
 | |
|         # build blocks
 | |
|         self.blocks = nn.ModuleList([
 | |
|             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, x_size):
 | |
|         for blk in self.blocks:
 | |
|             if self.use_checkpoint:
 | |
|                 x = checkpoint.checkpoint(blk, x, x_size)
 | |
|             else:
 | |
|                 x = blk(x, x_size)
 | |
|         if self.downsample is not None:
 | |
|             x = self.downsample(x)
 | |
|         return x
 | |
| 
 | |
|     def extra_repr(self) -> str:
 | |
|         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
 | |
| 
 | |
|     def _init_respostnorm(self):
 | |
|         for blk in self.blocks:
 | |
|             nn.init.constant_(blk.norm1.bias, 0)
 | |
|             nn.init.constant_(blk.norm1.weight, 0)
 | |
|             nn.init.constant_(blk.norm2.bias, 0)
 | |
|             nn.init.constant_(blk.norm2.weight, 0)
 | |
|             
 | |
| class PatchEmbed(nn.Module):
 | |
|     r""" Image to Patch Embedding
 | |
|     Args:
 | |
|         img_size (int): Image size.  Default: 224.
 | |
|         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=224, 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(1, 2)  # 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 RSTB(nn.Module):
 | |
|     """Residual Swin Transformer Block (RSTB).
 | |
| 
 | |
|     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
 | |
|         use_checkpoint (bool): Whether to use checkpointing to save memory. Default: False.
 | |
|         img_size: Input image size.
 | |
|         patch_size: Patch size.
 | |
|         resi_connection: The convolutional block before residual connection.
 | |
|     """
 | |
| 
 | |
|     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, use_checkpoint=False,
 | |
|                  img_size=224, patch_size=4, resi_connection='1conv'):
 | |
|         super(RSTB, self).__init__()
 | |
| 
 | |
|         self.dim = dim
 | |
|         self.input_resolution = input_resolution
 | |
| 
 | |
|         self.residual_group = BasicLayer(dim=dim,
 | |
|                                          input_resolution=input_resolution,
 | |
|                                          depth=depth,
 | |
|                                          num_heads=num_heads,
 | |
|                                          window_size=window_size,
 | |
|                                          mlp_ratio=mlp_ratio,
 | |
|                                          qkv_bias=qkv_bias, 
 | |
|                                          drop=drop, attn_drop=attn_drop,
 | |
|                                          drop_path=drop_path,
 | |
|                                          norm_layer=norm_layer,
 | |
|                                          downsample=downsample,
 | |
|                                          use_checkpoint=use_checkpoint)
 | |
| 
 | |
|         if resi_connection == '1conv':
 | |
|             self.conv = nn.Conv2d(dim, dim, 3, 1, 1)
 | |
|         elif resi_connection == '3conv':
 | |
|             # to save parameters and memory
 | |
|             self.conv = nn.Sequential(nn.Conv2d(dim, dim // 4, 3, 1, 1), nn.LeakyReLU(negative_slope=0.2, inplace=True),
 | |
|                                       nn.Conv2d(dim // 4, dim // 4, 1, 1, 0),
 | |
|                                       nn.LeakyReLU(negative_slope=0.2, inplace=True),
 | |
|                                       nn.Conv2d(dim // 4, dim, 3, 1, 1))
 | |
| 
 | |
|         self.patch_embed = PatchEmbed(
 | |
|             img_size=img_size, patch_size=patch_size, in_chans=dim, embed_dim=dim,
 | |
|             norm_layer=None)
 | |
| 
 | |
|         self.patch_unembed = PatchUnEmbed(
 | |
|             img_size=img_size, patch_size=patch_size, in_chans=dim, embed_dim=dim,
 | |
|             norm_layer=None)
 | |
| 
 | |
|     def forward(self, x, x_size):
 | |
|         return self.patch_embed(self.conv(self.patch_unembed(self.residual_group(x, x_size), x_size))) + x
 | |
| 
 | |
|     def flops(self):
 | |
|         flops = 0
 | |
|         flops += self.residual_group.flops()
 | |
|         H, W = self.input_resolution
 | |
|         flops += H * W * self.dim * self.dim * 9
 | |
|         flops += self.patch_embed.flops()
 | |
|         flops += self.patch_unembed.flops()
 | |
| 
 | |
|         return flops
 | |
| 
 | |
| class PatchUnEmbed(nn.Module):
 | |
|     r""" Image to Patch Unembedding
 | |
| 
 | |
|     Args:
 | |
|         img_size (int): Image size.  Default: 224.
 | |
|         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=224, 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
 | |
| 
 | |
|     def forward(self, x, x_size):
 | |
|         B, HW, C = x.shape
 | |
|         x = x.transpose(1, 2).view(B, self.embed_dim, x_size[0], x_size[1])  # B Ph*Pw C
 | |
|         return x
 | |
| 
 | |
|     def flops(self):
 | |
|         flops = 0
 | |
|         return flops
 | |
| 
 | |
| 
 | |
| class Upsample(nn.Sequential):
 | |
|     """Upsample module.
 | |
| 
 | |
|     Args:
 | |
|         scale (int): Scale factor. Supported scales: 2^n and 3.
 | |
|         num_feat (int): Channel number of intermediate features.
 | |
|     """
 | |
| 
 | |
|     def __init__(self, scale, num_feat):
 | |
|         m = []
 | |
|         if (scale & (scale - 1)) == 0:  # scale = 2^n
 | |
|             for _ in range(int(math.log(scale, 2))):
 | |
|                 m.append(nn.Conv2d(num_feat, 4 * num_feat, 3, 1, 1))
 | |
|                 m.append(nn.PixelShuffle(2))
 | |
|         elif scale == 3:
 | |
|             m.append(nn.Conv2d(num_feat, 9 * num_feat, 3, 1, 1))
 | |
|             m.append(nn.PixelShuffle(3))
 | |
|         else:
 | |
|             raise ValueError(f'scale {scale} is not supported. ' 'Supported scales: 2^n and 3.')
 | |
|         super(Upsample, self).__init__(*m)
 | |
|         
 | |
| class Upsample_hf(nn.Sequential):
 | |
|     """Upsample module.
 | |
| 
 | |
|     Args:
 | |
|         scale (int): Scale factor. Supported scales: 2^n and 3.
 | |
|         num_feat (int): Channel number of intermediate features.
 | |
|     """
 | |
| 
 | |
|     def __init__(self, scale, num_feat):
 | |
|         m = []
 | |
|         if (scale & (scale - 1)) == 0:  # scale = 2^n
 | |
|             for _ in range(int(math.log(scale, 2))):
 | |
|                 m.append(nn.Conv2d(num_feat, 4 * num_feat, 3, 1, 1))
 | |
|                 m.append(nn.PixelShuffle(2))
 | |
|         elif scale == 3:
 | |
|             m.append(nn.Conv2d(num_feat, 9 * num_feat, 3, 1, 1))
 | |
|             m.append(nn.PixelShuffle(3))
 | |
|         else:
 | |
|             raise ValueError(f'scale {scale} is not supported. ' 'Supported scales: 2^n and 3.')
 | |
|         super(Upsample_hf, self).__init__(*m)        
 | |
| 
 | |
| 
 | |
| class UpsampleOneStep(nn.Sequential):
 | |
|     """UpsampleOneStep module (the difference with Upsample is that it always only has 1conv + 1pixelshuffle)
 | |
|        Used in lightweight SR to save parameters.
 | |
| 
 | |
|     Args:
 | |
|         scale (int): Scale factor. Supported scales: 2^n and 3.
 | |
|         num_feat (int): Channel number of intermediate features.
 | |
| 
 | |
|     """
 | |
| 
 | |
|     def __init__(self, scale, num_feat, num_out_ch, input_resolution=None):
 | |
|         self.num_feat = num_feat
 | |
|         self.input_resolution = input_resolution
 | |
|         m = []
 | |
|         m.append(nn.Conv2d(num_feat, (scale ** 2) * num_out_ch, 3, 1, 1))
 | |
|         m.append(nn.PixelShuffle(scale))
 | |
|         super(UpsampleOneStep, self).__init__(*m)
 | |
| 
 | |
|     def flops(self):
 | |
|         H, W = self.input_resolution
 | |
|         flops = H * W * self.num_feat * 3 * 9
 | |
|         return flops
 | |
|     
 | |
|     
 | |
| 
 | |
| class Swin2SR(nn.Module):
 | |
|     r""" Swin2SR
 | |
|         A PyTorch impl of : `Swin2SR: SwinV2 Transformer for Compressed Image Super-Resolution and Restoration`.
 | |
| 
 | |
|     Args:
 | |
|         img_size (int | tuple(int)): Input image size. Default 64
 | |
|         patch_size (int | tuple(int)): Patch size. Default: 1
 | |
|         in_chans (int): Number of input image channels. Default: 3
 | |
|         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.Module): 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
 | |
|         use_checkpoint (bool): Whether to use checkpointing to save memory. Default: False
 | |
|         upscale: Upscale factor. 2/3/4/8 for image SR, 1 for denoising and compress artifact reduction
 | |
|         img_range: Image range. 1. or 255.
 | |
|         upsampler: The reconstruction reconstruction module. 'pixelshuffle'/'pixelshuffledirect'/'nearest+conv'/None
 | |
|         resi_connection: The convolutional block before residual connection. '1conv'/'3conv'
 | |
|     """
 | |
| 
 | |
|     def __init__(self, img_size=64, patch_size=1, in_chans=3,
 | |
|                  embed_dim=96, depths=[6, 6, 6, 6], num_heads=[6, 6, 6, 6],
 | |
|                  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,
 | |
|                  use_checkpoint=False, upscale=2, img_range=1., upsampler='', resi_connection='1conv',
 | |
|                  **kwargs):
 | |
|         super(Swin2SR, self).__init__()
 | |
|         num_in_ch = in_chans
 | |
|         num_out_ch = in_chans
 | |
|         num_feat = 64
 | |
|         self.img_range = img_range
 | |
|         if in_chans == 3:
 | |
|             rgb_mean = (0.4488, 0.4371, 0.4040)
 | |
|             self.mean = torch.Tensor(rgb_mean).view(1, 3, 1, 1)
 | |
|         else:
 | |
|             self.mean = torch.zeros(1, 1, 1, 1)
 | |
|         self.upscale = upscale
 | |
|         self.upsampler = upsampler
 | |
|         self.window_size = window_size
 | |
| 
 | |
|         #####################################################################################################
 | |
|         ################################### 1, shallow feature extraction ###################################
 | |
|         self.conv_first = nn.Conv2d(num_in_ch, embed_dim, 3, 1, 1)
 | |
| 
 | |
|         #####################################################################################################
 | |
|         ################################### 2, deep feature extraction ######################################
 | |
|         self.num_layers = len(depths)
 | |
|         self.embed_dim = embed_dim
 | |
|         self.ape = ape
 | |
|         self.patch_norm = patch_norm
 | |
|         self.num_features = embed_dim
 | |
|         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=embed_dim, 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
 | |
| 
 | |
|         # merge non-overlapping patches into image
 | |
|         self.patch_unembed = PatchUnEmbed(
 | |
|             img_size=img_size, patch_size=patch_size, in_chans=embed_dim, embed_dim=embed_dim,
 | |
|             norm_layer=norm_layer if self.patch_norm else None)
 | |
| 
 | |
|         # absolute position embedding
 | |
|         if self.ape:
 | |
|             self.absolute_pos_embed = nn.Parameter(torch.zeros(1, num_patches, embed_dim))
 | |
|             trunc_normal_(self.absolute_pos_embed, std=.02)
 | |
| 
 | |
|         self.pos_drop = nn.Dropout(p=drop_rate)
 | |
| 
 | |
|         # stochastic depth
 | |
|         dpr = [x.item() for x in torch.linspace(0, drop_path_rate, sum(depths))]  # stochastic depth decay rule
 | |
| 
 | |
|         # build Residual Swin Transformer blocks (RSTB)
 | |
|         self.layers = nn.ModuleList()
 | |
|         for i_layer in range(self.num_layers):
 | |
|             layer = RSTB(dim=embed_dim,
 | |
|                          input_resolution=(patches_resolution[0],
 | |
|                                            patches_resolution[1]),
 | |
|                          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])],  # no impact on SR results
 | |
|                          norm_layer=norm_layer,
 | |
|                          downsample=None,
 | |
|                          use_checkpoint=use_checkpoint,
 | |
|                          img_size=img_size,
 | |
|                          patch_size=patch_size,
 | |
|                          resi_connection=resi_connection
 | |
| 
 | |
|                          )
 | |
|             self.layers.append(layer)
 | |
|             
 | |
|         if self.upsampler == 'pixelshuffle_hf':
 | |
|             self.layers_hf = nn.ModuleList()
 | |
|             for i_layer in range(self.num_layers):
 | |
|                 layer = RSTB(dim=embed_dim,
 | |
|                              input_resolution=(patches_resolution[0],
 | |
|                                                patches_resolution[1]),
 | |
|                              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])],  # no impact on SR results
 | |
|                              norm_layer=norm_layer,
 | |
|                              downsample=None,
 | |
|                              use_checkpoint=use_checkpoint,
 | |
|                              img_size=img_size,
 | |
|                              patch_size=patch_size,
 | |
|                              resi_connection=resi_connection
 | |
| 
 | |
|                              )
 | |
|                 self.layers_hf.append(layer)
 | |
|                         
 | |
|         self.norm = norm_layer(self.num_features)
 | |
| 
 | |
|         # build the last conv layer in deep feature extraction
 | |
|         if resi_connection == '1conv':
 | |
|             self.conv_after_body = nn.Conv2d(embed_dim, embed_dim, 3, 1, 1)
 | |
|         elif resi_connection == '3conv':
 | |
|             # to save parameters and memory
 | |
|             self.conv_after_body = nn.Sequential(nn.Conv2d(embed_dim, embed_dim // 4, 3, 1, 1),
 | |
|                                                  nn.LeakyReLU(negative_slope=0.2, inplace=True),
 | |
|                                                  nn.Conv2d(embed_dim // 4, embed_dim // 4, 1, 1, 0),
 | |
|                                                  nn.LeakyReLU(negative_slope=0.2, inplace=True),
 | |
|                                                  nn.Conv2d(embed_dim // 4, embed_dim, 3, 1, 1))
 | |
| 
 | |
|         #####################################################################################################
 | |
|         ################################ 3, high quality image reconstruction ################################
 | |
|         if self.upsampler == 'pixelshuffle':
 | |
|             # for classical SR
 | |
|             self.conv_before_upsample = nn.Sequential(nn.Conv2d(embed_dim, num_feat, 3, 1, 1),
 | |
|                                                       nn.LeakyReLU(inplace=True))
 | |
|             self.upsample = Upsample(upscale, num_feat)
 | |
|             self.conv_last = nn.Conv2d(num_feat, num_out_ch, 3, 1, 1)
 | |
|         elif self.upsampler == 'pixelshuffle_aux':
 | |
|             self.conv_bicubic = nn.Conv2d(num_in_ch, num_feat, 3, 1, 1)
 | |
|             self.conv_before_upsample = nn.Sequential(
 | |
|                 nn.Conv2d(embed_dim, num_feat, 3, 1, 1),
 | |
|                 nn.LeakyReLU(inplace=True))
 | |
|             self.conv_aux = nn.Conv2d(num_feat, num_out_ch, 3, 1, 1)
 | |
|             self.conv_after_aux = nn.Sequential(
 | |
|                 nn.Conv2d(3, num_feat, 3, 1, 1),
 | |
|                 nn.LeakyReLU(inplace=True))            
 | |
|             self.upsample = Upsample(upscale, num_feat)
 | |
|             self.conv_last = nn.Conv2d(num_feat, num_out_ch, 3, 1, 1)
 | |
|             
 | |
|         elif self.upsampler == 'pixelshuffle_hf':
 | |
|             self.conv_before_upsample = nn.Sequential(nn.Conv2d(embed_dim, num_feat, 3, 1, 1),
 | |
|                                                       nn.LeakyReLU(inplace=True))
 | |
|             self.upsample = Upsample(upscale, num_feat)
 | |
|             self.upsample_hf = Upsample_hf(upscale, num_feat)
 | |
|             self.conv_last = nn.Conv2d(num_feat, num_out_ch, 3, 1, 1)
 | |
|             self.conv_first_hf = nn.Sequential(nn.Conv2d(num_feat, embed_dim, 3, 1, 1),
 | |
|                                                       nn.LeakyReLU(inplace=True))
 | |
|             self.conv_after_body_hf = nn.Conv2d(embed_dim, embed_dim, 3, 1, 1)
 | |
|             self.conv_before_upsample_hf = nn.Sequential(
 | |
|                 nn.Conv2d(embed_dim, num_feat, 3, 1, 1),
 | |
|                 nn.LeakyReLU(inplace=True))
 | |
|             self.conv_last_hf = nn.Conv2d(num_feat, num_out_ch, 3, 1, 1)
 | |
|             
 | |
|         elif self.upsampler == 'pixelshuffledirect':
 | |
|             # for lightweight SR (to save parameters)
 | |
|             self.upsample = UpsampleOneStep(upscale, embed_dim, num_out_ch,
 | |
|                                             (patches_resolution[0], patches_resolution[1]))
 | |
|         elif self.upsampler == 'nearest+conv':
 | |
|             # for real-world SR (less artifacts)
 | |
|             assert self.upscale == 4, 'only support x4 now.'
 | |
|             self.conv_before_upsample = nn.Sequential(nn.Conv2d(embed_dim, num_feat, 3, 1, 1),
 | |
|                                                       nn.LeakyReLU(inplace=True))
 | |
|             self.conv_up1 = nn.Conv2d(num_feat, num_feat, 3, 1, 1)
 | |
|             self.conv_up2 = nn.Conv2d(num_feat, num_feat, 3, 1, 1)
 | |
|             self.conv_hr = nn.Conv2d(num_feat, num_feat, 3, 1, 1)
 | |
|             self.conv_last = nn.Conv2d(num_feat, num_out_ch, 3, 1, 1)
 | |
|             self.lrelu = nn.LeakyReLU(negative_slope=0.2, inplace=True)
 | |
|         else:
 | |
|             # for image denoising and JPEG compression artifact reduction
 | |
|             self.conv_last = nn.Conv2d(embed_dim, num_out_ch, 3, 1, 1)
 | |
| 
 | |
|         self.apply(self._init_weights)
 | |
| 
 | |
|     def _init_weights(self, m):
 | |
|         if isinstance(m, nn.Linear):
 | |
|             trunc_normal_(m.weight, std=.02)
 | |
|             if isinstance(m, nn.Linear) and m.bias is not None:
 | |
|                 nn.init.constant_(m.bias, 0)
 | |
|         elif isinstance(m, nn.LayerNorm):
 | |
|             nn.init.constant_(m.bias, 0)
 | |
|             nn.init.constant_(m.weight, 1.0)
 | |
| 
 | |
|     @torch.jit.ignore
 | |
|     def no_weight_decay(self):
 | |
|         return {'absolute_pos_embed'}
 | |
| 
 | |
|     @torch.jit.ignore
 | |
|     def no_weight_decay_keywords(self):
 | |
|         return {'relative_position_bias_table'}
 | |
| 
 | |
|     def check_image_size(self, x):
 | |
|         _, _, h, w = x.size()
 | |
|         mod_pad_h = (self.window_size - h % self.window_size) % self.window_size
 | |
|         mod_pad_w = (self.window_size - w % self.window_size) % self.window_size
 | |
|         x = F.pad(x, (0, mod_pad_w, 0, mod_pad_h), 'reflect')
 | |
|         return x
 | |
| 
 | |
|     def forward_features(self, x):
 | |
|         x_size = (x.shape[2], x.shape[3])
 | |
|         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_size)
 | |
| 
 | |
|         x = self.norm(x)  # B L C
 | |
|         x = self.patch_unembed(x, x_size)
 | |
| 
 | |
|         return x
 | |
|     
 | |
|     def forward_features_hf(self, x):
 | |
|         x_size = (x.shape[2], x.shape[3])
 | |
|         x = self.patch_embed(x)
 | |
|         if self.ape:
 | |
|             x = x + self.absolute_pos_embed
 | |
|         x = self.pos_drop(x)
 | |
| 
 | |
|         for layer in self.layers_hf:
 | |
|             x = layer(x, x_size)
 | |
| 
 | |
|         x = self.norm(x)  # B L C
 | |
|         x = self.patch_unembed(x, x_size)
 | |
| 
 | |
|         return x    
 | |
| 
 | |
|     def forward(self, x):
 | |
|         H, W = x.shape[2:]
 | |
|         x = self.check_image_size(x)
 | |
| 
 | |
|         self.mean = self.mean.type_as(x)
 | |
|         x = (x - self.mean) * self.img_range
 | |
| 
 | |
|         if self.upsampler == 'pixelshuffle':
 | |
|             # for classical SR
 | |
|             x = self.conv_first(x)
 | |
|             x = self.conv_after_body(self.forward_features(x)) + x
 | |
|             x = self.conv_before_upsample(x)
 | |
|             x = self.conv_last(self.upsample(x))
 | |
|         elif self.upsampler == 'pixelshuffle_aux':
 | |
|             bicubic = F.interpolate(x, size=(H * self.upscale, W * self.upscale), mode='bicubic', align_corners=False)
 | |
|             bicubic = self.conv_bicubic(bicubic)
 | |
|             x = self.conv_first(x)
 | |
|             x = self.conv_after_body(self.forward_features(x)) + x
 | |
|             x = self.conv_before_upsample(x)
 | |
|             aux = self.conv_aux(x) # b, 3, LR_H, LR_W
 | |
|             x = self.conv_after_aux(aux)
 | |
|             x = self.upsample(x)[:, :, :H * self.upscale, :W * self.upscale] + bicubic[:, :, :H * self.upscale, :W * self.upscale]
 | |
|             x = self.conv_last(x)
 | |
|             aux = aux / self.img_range + self.mean
 | |
|         elif self.upsampler == 'pixelshuffle_hf':
 | |
|             # for classical SR with HF
 | |
|             x = self.conv_first(x)
 | |
|             x = self.conv_after_body(self.forward_features(x)) + x
 | |
|             x_before = self.conv_before_upsample(x)
 | |
|             x_out = self.conv_last(self.upsample(x_before))
 | |
|             
 | |
|             x_hf = self.conv_first_hf(x_before)
 | |
|             x_hf = self.conv_after_body_hf(self.forward_features_hf(x_hf)) + x_hf
 | |
|             x_hf = self.conv_before_upsample_hf(x_hf)
 | |
|             x_hf = self.conv_last_hf(self.upsample_hf(x_hf))
 | |
|             x = x_out + x_hf
 | |
|             x_hf = x_hf / self.img_range + self.mean
 | |
| 
 | |
|         elif self.upsampler == 'pixelshuffledirect':
 | |
|             # for lightweight SR
 | |
|             x = self.conv_first(x)
 | |
|             x = self.conv_after_body(self.forward_features(x)) + x
 | |
|             x = self.upsample(x)
 | |
|         elif self.upsampler == 'nearest+conv':
 | |
|             # for real-world SR
 | |
|             x = self.conv_first(x)
 | |
|             x = self.conv_after_body(self.forward_features(x)) + x
 | |
|             x = self.conv_before_upsample(x)
 | |
|             x = self.lrelu(self.conv_up1(torch.nn.functional.interpolate(x, scale_factor=2, mode='nearest')))
 | |
|             x = self.lrelu(self.conv_up2(torch.nn.functional.interpolate(x, scale_factor=2, mode='nearest')))
 | |
|             x = self.conv_last(self.lrelu(self.conv_hr(x)))
 | |
|         else:
 | |
|             # for image denoising and JPEG compression artifact reduction
 | |
|             x_first = self.conv_first(x)
 | |
|             res = self.conv_after_body(self.forward_features(x_first)) + x_first
 | |
|             x = x + self.conv_last(res)
 | |
|         
 | |
|         x = x / self.img_range + self.mean
 | |
|         if self.upsampler == "pixelshuffle_aux":
 | |
|             return x[:, :, :H*self.upscale, :W*self.upscale], aux
 | |
|         
 | |
|         elif self.upsampler == "pixelshuffle_hf":
 | |
|             x_out = x_out / self.img_range + self.mean
 | |
|             return x_out[:, :, :H*self.upscale, :W*self.upscale], x[:, :, :H*self.upscale, :W*self.upscale], x_hf[:, :, :H*self.upscale, :W*self.upscale]
 | |
|         
 | |
|         else:
 | |
|             return x[:, :, :H*self.upscale, :W*self.upscale]
 | |
| 
 | |
|     def flops(self):
 | |
|         flops = 0
 | |
|         H, W = self.patches_resolution
 | |
|         flops += H * W * 3 * self.embed_dim * 9
 | |
|         flops += self.patch_embed.flops()
 | |
|         for i, layer in enumerate(self.layers):
 | |
|             flops += layer.flops()
 | |
|         flops += H * W * 3 * self.embed_dim * self.embed_dim
 | |
|         flops += self.upsample.flops()
 | |
|         return flops
 | |
| 
 | |
| 
 | |
| if __name__ == '__main__':
 | |
|     upscale = 4
 | |
|     window_size = 8
 | |
|     height = (1024 // upscale // window_size + 1) * window_size
 | |
|     width = (720 // upscale // window_size + 1) * window_size
 | |
|     model = Swin2SR(upscale=2, img_size=(height, width),
 | |
|                    window_size=window_size, img_range=1., depths=[6, 6, 6, 6],
 | |
|                    embed_dim=60, num_heads=[6, 6, 6, 6], mlp_ratio=2, upsampler='pixelshuffledirect')
 | |
|     print(model)
 | |
|     print(height, width, model.flops() / 1e9)
 | |
| 
 | |
|     x = torch.randn((1, 3, height, width))
 | |
|     x = model(x)
 | |
|     print(x.shape) | 
