1225 lines
		
	
	
		
			43 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			1225 lines
		
	
	
		
			43 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| # pylint: skip-file
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| # -----------------------------------------------------------------------------------
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| # SwinIR: Image Restoration Using Swin Transformer, https://arxiv.org/abs/2108.10257
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| # Originally Written by Ze Liu, Modified by Jingyun Liang.
 | |
| # -----------------------------------------------------------------------------------
 | |
| 
 | |
| import math
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| import re
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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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| 
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| # Originally from the timm package
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| from .timm.drop import DropPath
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| from .timm.helpers import to_2tuple
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| from .timm.weight_init import trunc_normal_
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| 
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| 
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| class Mlp(nn.Module):
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|     def __init__(
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|         self,
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|         in_features,
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|         hidden_features=None,
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|         out_features=None,
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|         act_layer=nn.GELU,
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|         drop=0.0,
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|     ):
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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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| 
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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 = (
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|         x.permute(0, 1, 3, 2, 4, 5).contiguous().view(-1, window_size, window_size, C)
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|     )
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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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| 
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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(
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|         B, H // window_size, W // window_size, window_size, window_size, -1
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|     )
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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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| 
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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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| 
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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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|         qk_scale (float | None, optional): Override default qk scale of head_dim ** -0.5 if set
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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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|     """
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| 
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|     def __init__(
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|         self,
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|         dim,
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|         window_size,
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|         num_heads,
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|         qkv_bias=True,
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|         qk_scale=None,
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|         attn_drop=0.0,
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|         proj_drop=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.num_heads = num_heads
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|         head_dim = dim // num_heads
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|         self.scale = qk_scale or head_dim**-0.5
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| 
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|         # define a parameter table of relative position bias
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|         self.relative_position_bias_table = nn.Parameter(  # type: ignore
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|             torch.zeros((2 * window_size[0] - 1) * (2 * window_size[1] - 1), num_heads)
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|         )  # 2*Wh-1 * 2*Ww-1, nH
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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 = (
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|             coords_flatten[:, :, None] - coords_flatten[:, None, :]
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|         )  # 2, Wh*Ww, Wh*Ww
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|         relative_coords = relative_coords.permute(
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|             1, 2, 0
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|         ).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=qkv_bias)
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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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| 
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|         self.proj_drop = nn.Dropout(proj_drop)
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| 
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|         trunc_normal_(self.relative_position_bias_table, std=0.02)
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|         self.softmax = nn.Softmax(dim=-1)
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| 
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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 = (
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|             self.qkv(x)
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|             .reshape(B_, N, 3, self.num_heads, C // self.num_heads)
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|             .permute(2, 0, 3, 1, 4)
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|         )
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|         q, k, v = (
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|             qkv[0],
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|             qkv[1],
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|             qkv[2],
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|         )  # make torchscript happy (cannot use tensor as tuple)
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| 
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|         q = q * self.scale
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|         attn = q @ k.transpose(-2, -1)
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| 
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|         relative_position_bias = self.relative_position_bias_table[
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|             self.relative_position_index.view(-1)  # type: ignore
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|         ].view(
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|             self.window_size[0] * self.window_size[1],
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|             self.window_size[0] * self.window_size[1],
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|             -1,
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|         )  # Wh*Ww,Wh*Ww,nH
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|         relative_position_bias = relative_position_bias.permute(
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|             2, 0, 1
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|         ).contiguous()  # nH, Wh*Ww, Wh*Ww
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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(
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|                 1
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|             ).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}, 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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| 
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| 
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| class SwinTransformerBlock(nn.Module):
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|     r"""Swin Transformer Block.
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| 
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|     Args:
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|         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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|         qk_scale (float | None, optional): Override default qk scale of head_dim ** -0.5 if set.
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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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|     """
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| 
 | |
|     def __init__(
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|         self,
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|         dim,
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|         input_resolution,
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|         num_heads,
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|         window_size=7,
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|         shift_size=0,
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|         mlp_ratio=4.0,
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|         qkv_bias=True,
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|         qk_scale=None,
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|         drop=0.0,
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|         attn_drop=0.0,
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|         drop_path=0.0,
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|         act_layer=nn.GELU,
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|         norm_layer=nn.LayerNorm,
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|     ):
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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 (
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|             0 <= self.shift_size < self.window_size
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|         ), "shift_size must in 0-window_size"
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| 
 | |
|         self.norm1 = norm_layer(dim)
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|         self.attn = WindowAttention(
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|             dim,
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|             window_size=to_2tuple(self.window_size),
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|             num_heads=num_heads,
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|             qkv_bias=qkv_bias,
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|             qk_scale=qk_scale,
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|             attn_drop=attn_drop,
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|             proj_drop=drop,
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|         )
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| 
 | |
|         self.drop_path = DropPath(drop_path) if drop_path > 0.0 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(
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|             in_features=dim,
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|             hidden_features=mlp_hidden_dim,
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|             act_layer=act_layer,
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|             drop=drop,
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|         )
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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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| 
 | |
|         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 = (
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|             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 = (
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|             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:
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|             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(
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|             img_mask, self.window_size
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|         )  # nW, window_size, window_size, 1
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|         mask_windows = mask_windows.view(-1, self.window_size * self.window_size)
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|         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)
 | |
|         )
 | |
| 
 | |
|         return attn_mask
 | |
| 
 | |
|     def forward(self, x, x_size):
 | |
|         H, W = x_size
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|         B, L, C = x.shape
 | |
|         # assert L == H * W, "input feature has wrong size"
 | |
| 
 | |
|         shortcut = x
 | |
|         x = self.norm1(x)
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|         x = x.view(B, H, W, C)
 | |
| 
 | |
|         # cyclic shift
 | |
|         if self.shift_size > 0:
 | |
|             shifted_x = torch.roll(
 | |
|                 x, shifts=(-self.shift_size, -self.shift_size), dims=(1, 2)
 | |
|             )
 | |
|         else:
 | |
|             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
 | |
|         x_windows = x_windows.view(
 | |
|             -1, self.window_size * self.window_size, C
 | |
|         )  # nW*B, window_size*window_size, C
 | |
| 
 | |
|         # 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:
 | |
|             attn_windows = self.attn(
 | |
|                 x_windows, mask=self.attn_mask
 | |
|             )  # nW*B, window_size*window_size, C
 | |
|         else:
 | |
|             attn_windows = self.attn(
 | |
|                 x_windows, mask=self.calculate_mask(x_size).to(x.device)
 | |
|             )
 | |
| 
 | |
|         # 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
 | |
|         x = x.view(B, H * W, C)
 | |
| 
 | |
|         # FFN
 | |
|         x = shortcut + self.drop_path(x)
 | |
|         x = x + self.drop_path(self.mlp(self.norm2(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(4 * 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
 | |
|         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.norm(x)
 | |
|         x = self.reduction(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 * W * self.dim
 | |
|         flops += (H // 2) * (W // 2) * 4 * self.dim * 2 * self.dim
 | |
|         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
 | |
|         qk_scale (float | None, optional): Override default qk scale of head_dim ** -0.5 if set.
 | |
|         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.
 | |
|     """
 | |
| 
 | |
|     def __init__(
 | |
|         self,
 | |
|         dim,
 | |
|         input_resolution,
 | |
|         depth,
 | |
|         num_heads,
 | |
|         window_size,
 | |
|         mlp_ratio=4.0,
 | |
|         qkv_bias=True,
 | |
|         qk_scale=None,
 | |
|         drop=0.0,
 | |
|         attn_drop=0.0,
 | |
|         drop_path=0.0,
 | |
|         norm_layer=nn.LayerNorm,
 | |
|         downsample=None,
 | |
|         use_checkpoint=False,
 | |
|     ):
 | |
|         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,
 | |
|                     qk_scale=qk_scale,
 | |
|                     drop=drop,
 | |
|                     attn_drop=attn_drop,
 | |
|                     drop_path=drop_path[i]
 | |
|                     if isinstance(drop_path, list)
 | |
|                     else drop_path,
 | |
|                     norm_layer=norm_layer,
 | |
|                 )
 | |
|                 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()  # type: ignore
 | |
|         if self.downsample is not None:
 | |
|             flops += self.downsample.flops()
 | |
|         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
 | |
|         qk_scale (float | None, optional): Override default qk scale of head_dim ** -0.5 if set.
 | |
|         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=4.0,
 | |
|         qkv_bias=True,
 | |
|         qk_scale=None,
 | |
|         drop=0.0,
 | |
|         attn_drop=0.0,
 | |
|         drop_path=0.0,
 | |
|         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,
 | |
|             qk_scale=qk_scale,
 | |
|             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=0,
 | |
|             embed_dim=dim,
 | |
|             norm_layer=None,
 | |
|         )
 | |
| 
 | |
|         self.patch_unembed = PatchUnEmbed(
 | |
|             img_size=img_size,
 | |
|             patch_size=patch_size,
 | |
|             in_chans=0,
 | |
|             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 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],  # type: ignore
 | |
|             img_size[1] // patch_size[1],  # type: ignore
 | |
|         ]
 | |
|         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
 | |
| 
 | |
|         if norm_layer is not None:
 | |
|             self.norm = norm_layer(embed_dim)
 | |
|         else:
 | |
|             self.norm = None
 | |
| 
 | |
|     def forward(self, x):
 | |
|         x = 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):
 | |
|         flops = 0
 | |
|         H, W = self.img_size
 | |
|         if self.norm is not None:
 | |
|             flops += H * W * self.embed_dim  # type: ignore
 | |
|         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],  # type: ignore
 | |
|             img_size[1] // patch_size[1],  # type: ignore
 | |
|         ]
 | |
|         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 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  # type: ignore
 | |
|         flops = H * W * self.num_feat * 3 * 9
 | |
|         return flops
 | |
| 
 | |
| 
 | |
| class SwinIR(nn.Module):
 | |
|     r"""SwinIR
 | |
|         A PyTorch impl of : `SwinIR: Image Restoration Using Swin Transformer`, based on Swin Transformer.
 | |
| 
 | |
|     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
 | |
|         qk_scale (float): Override default qk scale of head_dim ** -0.5 if set. Default: None
 | |
|         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,
 | |
|         state_dict,
 | |
|         **kwargs,
 | |
|     ):
 | |
|         super(SwinIR, self).__init__()
 | |
| 
 | |
|         # Defaults
 | |
|         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 = 4.0
 | |
|         qkv_bias = True
 | |
|         qk_scale = None
 | |
|         drop_rate = 0.0
 | |
|         attn_drop_rate = 0.0
 | |
|         drop_path_rate = 0.1
 | |
|         norm_layer = nn.LayerNorm
 | |
|         ape = False
 | |
|         patch_norm = True
 | |
|         use_checkpoint = False
 | |
|         upscale = 2
 | |
|         img_range = 1.0
 | |
|         upsampler = ""
 | |
|         resi_connection = "1conv"
 | |
|         num_feat = 64
 | |
|         num_in_ch = in_chans
 | |
|         num_out_ch = in_chans
 | |
|         supports_fp16 = True
 | |
|         self.start_unshuffle = 1
 | |
| 
 | |
|         self.model_arch = "SwinIR"
 | |
|         self.sub_type = "SR"
 | |
|         self.state = state_dict
 | |
|         if "params_ema" in self.state:
 | |
|             self.state = self.state["params_ema"]
 | |
|         elif "params" in self.state:
 | |
|             self.state = self.state["params"]
 | |
| 
 | |
|         state_keys = self.state.keys()
 | |
| 
 | |
|         if "conv_before_upsample.0.weight" in state_keys:
 | |
|             if "conv_up1.weight" in state_keys:
 | |
|                 upsampler = "nearest+conv"
 | |
|             else:
 | |
|                 upsampler = "pixelshuffle"
 | |
|                 supports_fp16 = False
 | |
|         elif "upsample.0.weight" in state_keys:
 | |
|             upsampler = "pixelshuffledirect"
 | |
|         else:
 | |
|             upsampler = ""
 | |
| 
 | |
|         num_feat = (
 | |
|             self.state.get("conv_before_upsample.0.weight", None).shape[1]
 | |
|             if self.state.get("conv_before_upsample.weight", None)
 | |
|             else 64
 | |
|         )
 | |
| 
 | |
|         if "conv_first.1.weight" in self.state:
 | |
|             self.state["conv_first.weight"] = self.state.pop("conv_first.1.weight")
 | |
|             self.state["conv_first.bias"] = self.state.pop("conv_first.1.bias")
 | |
|             self.start_unshuffle = round(math.sqrt(self.state["conv_first.weight"].shape[1] // 3))
 | |
| 
 | |
|         num_in_ch = self.state["conv_first.weight"].shape[1]
 | |
|         in_chans = num_in_ch
 | |
|         if "conv_last.weight" in state_keys:
 | |
|             num_out_ch = self.state["conv_last.weight"].shape[0]
 | |
|         else:
 | |
|             num_out_ch = num_in_ch
 | |
| 
 | |
|         upscale = 1
 | |
|         if upsampler == "nearest+conv":
 | |
|             upsample_keys = [
 | |
|                 x for x in state_keys if "conv_up" in x and "bias" not in x
 | |
|             ]
 | |
| 
 | |
|             for upsample_key in upsample_keys:
 | |
|                 upscale *= 2
 | |
|         elif upsampler == "pixelshuffle":
 | |
|             upsample_keys = [
 | |
|                 x
 | |
|                 for x in state_keys
 | |
|                 if "upsample" in x and "conv" not in x and "bias" not in x
 | |
|             ]
 | |
|             for upsample_key in upsample_keys:
 | |
|                 shape = self.state[upsample_key].shape[0]
 | |
|                 upscale *= math.sqrt(shape // num_feat)
 | |
|             upscale = int(upscale)
 | |
|         elif upsampler == "pixelshuffledirect":
 | |
|             upscale = int(
 | |
|                 math.sqrt(self.state["upsample.0.bias"].shape[0] // num_out_ch)
 | |
|             )
 | |
| 
 | |
|         max_layer_num = 0
 | |
|         max_block_num = 0
 | |
|         for key in state_keys:
 | |
|             result = re.match(
 | |
|                 r"layers.(\d*).residual_group.blocks.(\d*).norm1.weight", key
 | |
|             )
 | |
|             if result:
 | |
|                 layer_num, block_num = result.groups()
 | |
|                 max_layer_num = max(max_layer_num, int(layer_num))
 | |
|                 max_block_num = max(max_block_num, int(block_num))
 | |
| 
 | |
|         depths = [max_block_num + 1 for _ in range(max_layer_num + 1)]
 | |
| 
 | |
|         if (
 | |
|             "layers.0.residual_group.blocks.0.attn.relative_position_bias_table"
 | |
|             in state_keys
 | |
|         ):
 | |
|             num_heads_num = self.state[
 | |
|                 "layers.0.residual_group.blocks.0.attn.relative_position_bias_table"
 | |
|             ].shape[-1]
 | |
|             num_heads = [num_heads_num for _ in range(max_layer_num + 1)]
 | |
|         else:
 | |
|             num_heads = depths
 | |
| 
 | |
|         embed_dim = self.state["conv_first.weight"].shape[0]
 | |
| 
 | |
|         mlp_ratio = float(
 | |
|             self.state["layers.0.residual_group.blocks.0.mlp.fc1.bias"].shape[0]
 | |
|             / embed_dim
 | |
|         )
 | |
| 
 | |
|         # TODO: could actually count the layers, but this should do
 | |
|         if "layers.0.conv.4.weight" in state_keys:
 | |
|             resi_connection = "3conv"
 | |
|         else:
 | |
|             resi_connection = "1conv"
 | |
| 
 | |
|         window_size = int(
 | |
|             math.sqrt(
 | |
|                 self.state[
 | |
|                     "layers.0.residual_group.blocks.0.attn.relative_position_index"
 | |
|                 ].shape[0]
 | |
|             )
 | |
|         )
 | |
| 
 | |
|         if "layers.0.residual_group.blocks.1.attn_mask" in state_keys:
 | |
|             img_size = int(
 | |
|                 math.sqrt(
 | |
|                     self.state["layers.0.residual_group.blocks.1.attn_mask"].shape[0]
 | |
|                 )
 | |
|                 * window_size
 | |
|             )
 | |
| 
 | |
|         # The JPEG models are the only ones with window-size 7, and they also use this range
 | |
|         img_range = 255.0 if window_size == 7 else 1.0
 | |
| 
 | |
|         self.in_nc = num_in_ch
 | |
|         self.out_nc = num_out_ch
 | |
|         self.num_feat = num_feat
 | |
|         self.embed_dim = embed_dim
 | |
|         self.num_heads = num_heads
 | |
|         self.depths = depths
 | |
|         self.window_size = window_size
 | |
|         self.mlp_ratio = mlp_ratio
 | |
|         self.scale = upscale / self.start_unshuffle
 | |
|         self.upsampler = upsampler
 | |
|         self.img_size = img_size
 | |
|         self.img_range = img_range
 | |
|         self.resi_connection = resi_connection
 | |
| 
 | |
|         self.supports_fp16 = False  # Too much weirdness to support this at the moment
 | |
|         self.supports_bfp16 = True
 | |
|         self.min_size_restriction = 16
 | |
| 
 | |
|         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(  # type: ignore
 | |
|                 torch.zeros(1, num_patches, embed_dim)
 | |
|             )
 | |
|             trunc_normal_(self.absolute_pos_embed, std=0.02)
 | |
| 
 | |
|         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,
 | |
|                 qk_scale=qk_scale,
 | |
|                 drop=drop_rate,
 | |
|                 attn_drop=attn_drop_rate,
 | |
|                 drop_path=dpr[
 | |
|                     sum(depths[:i_layer]) : sum(depths[: i_layer + 1])  # type: ignore
 | |
|                 ],  # 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)
 | |
|         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 == "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)
 | |
|             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)
 | |
|             if self.upscale == 4:
 | |
|                 self.conv_up2 = nn.Conv2d(num_feat, num_feat, 3, 1, 1)
 | |
|             elif self.upscale == 8:
 | |
|                 self.conv_up2 = nn.Conv2d(num_feat, num_feat, 3, 1, 1)
 | |
|                 self.conv_up3 = 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)
 | |
|         self.load_state_dict(self.state, strict=False)
 | |
| 
 | |
|     def _init_weights(self, m):
 | |
|         if isinstance(m, nn.Linear):
 | |
|             trunc_normal_(m.weight, std=0.02)
 | |
|             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  # type: ignore
 | |
|     def no_weight_decay(self):
 | |
|         return {"absolute_pos_embed"}
 | |
| 
 | |
|     @torch.jit.ignore  # type: 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(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.start_unshuffle > 1:
 | |
|             x = torch.nn.functional.pixel_unshuffle(x, self.start_unshuffle)
 | |
| 
 | |
|         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 == "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")  # type: ignore
 | |
|                 )
 | |
|             )
 | |
|             if self.upscale == 4:
 | |
|                 x = self.lrelu(
 | |
|                     self.conv_up2(
 | |
|                         torch.nn.functional.interpolate(  # type: ignore
 | |
|                             x, scale_factor=2, mode="nearest"
 | |
|                         )
 | |
|                     )
 | |
|                 )
 | |
|             elif self.upscale == 8:
 | |
|                 x = self.lrelu(self.conv_up2(torch.nn.functional.interpolate(x, scale_factor=2, mode='nearest')))
 | |
|                 x = self.lrelu(self.conv_up3(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
 | |
| 
 | |
|         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()  # type: ignore
 | |
|         flops += H * W * 3 * self.embed_dim * self.embed_dim
 | |
|         flops += self.upsample.flops()  # type: ignore
 | |
|         return flops
 |