HikariDawn's picture
feat: DAT and comparison
9bf54b1
'''
DAT network from https://github.com/zhengchen1999/DAT (https://openaccess.thecvf.com/content/ICCV2023/papers/Chen_Dual_Aggregation_Transformer_for_Image_Super-Resolution_ICCV_2023_paper.pdf)
'''
import torch
import torch.nn as nn
import torch.utils.checkpoint as checkpoint
from torch import Tensor
from torch.nn import functional as F
from timm.models.layers import DropPath, trunc_normal_
from einops.layers.torch import Rearrange
from einops import rearrange
import math
import numpy as np
def img2windows(img, H_sp, W_sp):
"""
Input: Image (B, C, H, W)
Output: Window Partition (B', N, C)
"""
B, C, H, W = img.shape
img_reshape = img.view(B, C, H // H_sp, H_sp, W // W_sp, W_sp)
img_perm = img_reshape.permute(0, 2, 4, 3, 5, 1).contiguous().reshape(-1, H_sp* W_sp, C)
return img_perm
def windows2img(img_splits_hw, H_sp, W_sp, H, W):
"""
Input: Window Partition (B', N, C)
Output: Image (B, H, W, C)
"""
B = int(img_splits_hw.shape[0] / (H * W / H_sp / W_sp))
img = img_splits_hw.view(B, H // H_sp, W // W_sp, H_sp, W_sp, -1)
img = img.permute(0, 1, 3, 2, 4, 5).contiguous().view(B, H, W, -1)
return img
class SpatialGate(nn.Module):
""" Spatial-Gate.
Args:
dim (int): Half of input channels.
"""
def __init__(self, dim):
super().__init__()
self.norm = nn.LayerNorm(dim)
self.conv = nn.Conv2d(dim, dim, kernel_size=3, stride=1, padding=1, groups=dim) # DW Conv
def forward(self, x, H, W):
# Split
x1, x2 = x.chunk(2, dim = -1)
B, N, C = x.shape
x2 = self.conv(self.norm(x2).transpose(1, 2).contiguous().view(B, C//2, H, W)).flatten(2).transpose(-1, -2).contiguous()
return x1 * x2
class SGFN(nn.Module):
""" Spatial-Gate Feed-Forward Network.
Args:
in_features (int): Number of input channels.
hidden_features (int | None): Number of hidden channels. Default: None
out_features (int | None): Number of output channels. Default: None
act_layer (nn.Module): Activation layer. Default: nn.GELU
drop (float): Dropout rate. Default: 0.0
"""
def __init__(self, in_features, hidden_features=None, out_features=None, act_layer=nn.GELU, drop=0.):
super().__init__()
out_features = out_features or in_features
hidden_features = hidden_features or in_features
self.fc1 = nn.Linear(in_features, hidden_features)
self.act = act_layer()
self.sg = SpatialGate(hidden_features//2)
self.fc2 = nn.Linear(hidden_features//2, out_features)
self.drop = nn.Dropout(drop)
def forward(self, x, H, W):
"""
Input: x: (B, H*W, C), H, W
Output: x: (B, H*W, C)
"""
x = self.fc1(x)
x = self.act(x)
x = self.drop(x)
x = self.sg(x, H, W)
x = self.drop(x)
x = self.fc2(x)
x = self.drop(x)
return x
class DynamicPosBias(nn.Module):
# The implementation builds on Crossformer code https://github.com/cheerss/CrossFormer/blob/main/models/crossformer.py
""" Dynamic Relative Position Bias.
Args:
dim (int): Number of input channels.
num_heads (int): Number of attention heads.
residual (bool): If True, use residual strage to connect conv.
"""
def __init__(self, dim, num_heads, residual):
super().__init__()
self.residual = residual
self.num_heads = num_heads
self.pos_dim = dim // 4
self.pos_proj = nn.Linear(2, self.pos_dim)
self.pos1 = nn.Sequential(
nn.LayerNorm(self.pos_dim),
nn.ReLU(inplace=True),
nn.Linear(self.pos_dim, self.pos_dim),
)
self.pos2 = nn.Sequential(
nn.LayerNorm(self.pos_dim),
nn.ReLU(inplace=True),
nn.Linear(self.pos_dim, self.pos_dim)
)
self.pos3 = nn.Sequential(
nn.LayerNorm(self.pos_dim),
nn.ReLU(inplace=True),
nn.Linear(self.pos_dim, self.num_heads)
)
def forward(self, biases):
if self.residual:
pos = self.pos_proj(biases) # 2Gh-1 * 2Gw-1, heads
pos = pos + self.pos1(pos)
pos = pos + self.pos2(pos)
pos = self.pos3(pos)
else:
pos = self.pos3(self.pos2(self.pos1(self.pos_proj(biases))))
return pos
class Spatial_Attention(nn.Module):
""" Spatial Window Self-Attention.
It supports rectangle window (containing square window).
Args:
dim (int): Number of input channels.
idx (int): The indentix of window. (0/1)
split_size (tuple(int)): Height and Width of spatial window.
dim_out (int | None): The dimension of the attention output. Default: None
num_heads (int): Number of attention heads. Default: 6
attn_drop (float): Dropout ratio of attention weight. Default: 0.0
proj_drop (float): Dropout ratio of output. Default: 0.0
qk_scale (float | None): Override default qk scale of head_dim ** -0.5 if set
position_bias (bool): The dynamic relative position bias. Default: True
"""
def __init__(self, dim, idx, split_size=[8,8], dim_out=None, num_heads=6, attn_drop=0., proj_drop=0., qk_scale=None, position_bias=True):
super().__init__()
self.dim = dim
self.dim_out = dim_out or dim
self.split_size = split_size
self.num_heads = num_heads
self.idx = idx
self.position_bias = position_bias
head_dim = dim // num_heads
self.scale = qk_scale or head_dim ** -0.5
if idx == 0:
H_sp, W_sp = self.split_size[0], self.split_size[1]
elif idx == 1:
W_sp, H_sp = self.split_size[0], self.split_size[1]
else:
print ("ERROR MODE", idx)
exit(0)
self.H_sp = H_sp
self.W_sp = W_sp
if self.position_bias:
self.pos = DynamicPosBias(self.dim // 4, self.num_heads, residual=False)
# generate mother-set
position_bias_h = torch.arange(1 - self.H_sp, self.H_sp)
position_bias_w = torch.arange(1 - self.W_sp, self.W_sp)
biases = torch.stack(torch.meshgrid([position_bias_h, position_bias_w]))
biases = biases.flatten(1).transpose(0, 1).contiguous().float()
self.register_buffer('rpe_biases', biases)
# get pair-wise relative position index for each token inside the window
coords_h = torch.arange(self.H_sp)
coords_w = torch.arange(self.W_sp)
coords = torch.stack(torch.meshgrid([coords_h, coords_w]))
coords_flatten = torch.flatten(coords, 1)
relative_coords = coords_flatten[:, :, None] - coords_flatten[:, None, :]
relative_coords = relative_coords.permute(1, 2, 0).contiguous()
relative_coords[:, :, 0] += self.H_sp - 1
relative_coords[:, :, 1] += self.W_sp - 1
relative_coords[:, :, 0] *= 2 * self.W_sp - 1
relative_position_index = relative_coords.sum(-1)
self.register_buffer('relative_position_index', relative_position_index)
self.attn_drop = nn.Dropout(attn_drop)
def im2win(self, x, H, W):
B, N, C = x.shape
x = x.transpose(-2,-1).contiguous().view(B, C, H, W)
x = img2windows(x, self.H_sp, self.W_sp)
x = x.reshape(-1, self.H_sp* self.W_sp, self.num_heads, C // self.num_heads).permute(0, 2, 1, 3).contiguous()
return x
def forward(self, qkv, H, W, mask=None):
"""
Input: qkv: (B, 3*L, C), H, W, mask: (B, N, N), N is the window size
Output: x (B, H, W, C)
"""
q,k,v = qkv[0], qkv[1], qkv[2]
B, L, C = q.shape
assert L == H * W, "flatten img_tokens has wrong size"
# partition the q,k,v, image to window
q = self.im2win(q, H, W)
k = self.im2win(k, H, W)
v = self.im2win(v, H, W)
q = q * self.scale
attn = (q @ k.transpose(-2, -1)) # B head N C @ B head C N --> B head N N
# calculate drpe
if self.position_bias:
pos = self.pos(self.rpe_biases)
# select position bias
relative_position_bias = pos[self.relative_position_index.view(-1)].view(
self.H_sp * self.W_sp, self.H_sp * self.W_sp, -1)
relative_position_bias = relative_position_bias.permute(2, 0, 1).contiguous()
attn = attn + relative_position_bias.unsqueeze(0)
N = attn.shape[3]
# use mask for shift window
if mask is not None:
nW = mask.shape[0]
attn = attn.view(B, nW, self.num_heads, N, N) + mask.unsqueeze(1).unsqueeze(0)
attn = attn.view(-1, self.num_heads, N, N)
attn = nn.functional.softmax(attn, dim=-1, dtype=attn.dtype)
attn = self.attn_drop(attn)
x = (attn @ v)
x = x.transpose(1, 2).reshape(-1, self.H_sp* self.W_sp, C) # B head N N @ B head N C
# merge the window, window to image
x = windows2img(x, self.H_sp, self.W_sp, H, W) # B H' W' C
return x
class Adaptive_Spatial_Attention(nn.Module):
# The implementation builds on CAT code https://github.com/Zhengchen1999/CAT
""" Adaptive Spatial Self-Attention
Args:
dim (int): Number of input channels.
num_heads (int): Number of attention heads. Default: 6
split_size (tuple(int)): Height and Width of spatial window.
shift_size (tuple(int)): Shift size for spatial window.
qkv_bias (bool): If True, add a learnable bias to query, key, value. Default: True
qk_scale (float | None): Override default qk scale of head_dim ** -0.5 if set.
drop (float): Dropout rate. Default: 0.0
attn_drop (float): Attention dropout rate. Default: 0.0
rg_idx (int): The indentix of Residual Group (RG)
b_idx (int): The indentix of Block in each RG
"""
def __init__(self, dim, num_heads,
reso=64, split_size=[8,8], shift_size=[1,2], qkv_bias=False, qk_scale=None,
drop=0., attn_drop=0., rg_idx=0, b_idx=0):
super().__init__()
self.dim = dim
self.num_heads = num_heads
self.split_size = split_size
self.shift_size = shift_size
self.b_idx = b_idx
self.rg_idx = rg_idx
self.patches_resolution = reso
self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
assert 0 <= self.shift_size[0] < self.split_size[0], "shift_size must in 0-split_size0"
assert 0 <= self.shift_size[1] < self.split_size[1], "shift_size must in 0-split_size1"
self.branch_num = 2
self.proj = nn.Linear(dim, dim)
self.proj_drop = nn.Dropout(drop)
self.attns = nn.ModuleList([
Spatial_Attention(
dim//2, idx = i,
split_size=split_size, num_heads=num_heads//2, dim_out=dim//2,
qk_scale=qk_scale, attn_drop=attn_drop, proj_drop=drop, position_bias=True)
for i in range(self.branch_num)])
if (self.rg_idx % 2 == 0 and self.b_idx > 0 and (self.b_idx - 2) % 4 == 0) or (self.rg_idx % 2 != 0 and self.b_idx % 4 == 0):
attn_mask = self.calculate_mask(self.patches_resolution, self.patches_resolution)
self.register_buffer("attn_mask_0", attn_mask[0])
self.register_buffer("attn_mask_1", attn_mask[1])
else:
attn_mask = None
self.register_buffer("attn_mask_0", None)
self.register_buffer("attn_mask_1", None)
self.dwconv = nn.Sequential(
nn.Conv2d(dim, dim, kernel_size=3, stride=1, padding=1,groups=dim),
nn.BatchNorm2d(dim),
nn.GELU()
)
self.channel_interaction = nn.Sequential(
nn.AdaptiveAvgPool2d(1),
nn.Conv2d(dim, dim // 8, kernel_size=1),
nn.BatchNorm2d(dim // 8),
nn.GELU(),
nn.Conv2d(dim // 8, dim, kernel_size=1),
)
self.spatial_interaction = nn.Sequential(
nn.Conv2d(dim, dim // 16, kernel_size=1),
nn.BatchNorm2d(dim // 16),
nn.GELU(),
nn.Conv2d(dim // 16, 1, kernel_size=1)
)
def calculate_mask(self, H, W):
# The implementation builds on Swin Transformer code https://github.com/microsoft/Swin-Transformer/blob/main/models/swin_transformer.py
# calculate attention mask for shift window
img_mask_0 = torch.zeros((1, H, W, 1)) # 1 H W 1 idx=0
img_mask_1 = torch.zeros((1, H, W, 1)) # 1 H W 1 idx=1
h_slices_0 = (slice(0, -self.split_size[0]),
slice(-self.split_size[0], -self.shift_size[0]),
slice(-self.shift_size[0], None))
w_slices_0 = (slice(0, -self.split_size[1]),
slice(-self.split_size[1], -self.shift_size[1]),
slice(-self.shift_size[1], None))
h_slices_1 = (slice(0, -self.split_size[1]),
slice(-self.split_size[1], -self.shift_size[1]),
slice(-self.shift_size[1], None))
w_slices_1 = (slice(0, -self.split_size[0]),
slice(-self.split_size[0], -self.shift_size[0]),
slice(-self.shift_size[0], None))
cnt = 0
for h in h_slices_0:
for w in w_slices_0:
img_mask_0[:, h, w, :] = cnt
cnt += 1
cnt = 0
for h in h_slices_1:
for w in w_slices_1:
img_mask_1[:, h, w, :] = cnt
cnt += 1
# calculate mask for window-0
img_mask_0 = img_mask_0.view(1, H // self.split_size[0], self.split_size[0], W // self.split_size[1], self.split_size[1], 1)
img_mask_0 = img_mask_0.permute(0, 1, 3, 2, 4, 5).contiguous().view(-1, self.split_size[0], self.split_size[1], 1) # nW, sw[0], sw[1], 1
mask_windows_0 = img_mask_0.view(-1, self.split_size[0] * self.split_size[1])
attn_mask_0 = mask_windows_0.unsqueeze(1) - mask_windows_0.unsqueeze(2)
attn_mask_0 = attn_mask_0.masked_fill(attn_mask_0 != 0, float(-100.0)).masked_fill(attn_mask_0 == 0, float(0.0))
# calculate mask for window-1
img_mask_1 = img_mask_1.view(1, H // self.split_size[1], self.split_size[1], W // self.split_size[0], self.split_size[0], 1)
img_mask_1 = img_mask_1.permute(0, 1, 3, 2, 4, 5).contiguous().view(-1, self.split_size[1], self.split_size[0], 1) # nW, sw[1], sw[0], 1
mask_windows_1 = img_mask_1.view(-1, self.split_size[1] * self.split_size[0])
attn_mask_1 = mask_windows_1.unsqueeze(1) - mask_windows_1.unsqueeze(2)
attn_mask_1 = attn_mask_1.masked_fill(attn_mask_1 != 0, float(-100.0)).masked_fill(attn_mask_1 == 0, float(0.0))
return attn_mask_0, attn_mask_1
def forward(self, x, H, W):
"""
Input: x: (B, H*W, C), H, W
Output: x: (B, H*W, C)
"""
B, L, C = x.shape
assert L == H * W, "flatten img_tokens has wrong size"
qkv = self.qkv(x).reshape(B, -1, 3, C).permute(2, 0, 1, 3) # 3, B, HW, C
# V without partition
v = qkv[2].transpose(-2,-1).contiguous().view(B, C, H, W)
# image padding
max_split_size = max(self.split_size[0], self.split_size[1])
pad_l = pad_t = 0
pad_r = (max_split_size - W % max_split_size) % max_split_size
pad_b = (max_split_size - H % max_split_size) % max_split_size
qkv = qkv.reshape(3*B, H, W, C).permute(0, 3, 1, 2) # 3B C H W
qkv = F.pad(qkv, (pad_l, pad_r, pad_t, pad_b)).reshape(3, B, C, -1).transpose(-2, -1) # l r t b
_H = pad_b + H
_W = pad_r + W
_L = _H * _W
# window-0 and window-1 on split channels [C/2, C/2]; for square windows (e.g., 8x8), window-0 and window-1 can be merged
# shift in block: (0, 4, 8, ...), (2, 6, 10, ...), (0, 4, 8, ...), (2, 6, 10, ...), ...
if (self.rg_idx % 2 == 0 and self.b_idx > 0 and (self.b_idx - 2) % 4 == 0) or (self.rg_idx % 2 != 0 and self.b_idx % 4 == 0):
qkv = qkv.view(3, B, _H, _W, C)
qkv_0 = torch.roll(qkv[:,:,:,:,:C//2], shifts=(-self.shift_size[0], -self.shift_size[1]), dims=(2, 3))
qkv_0 = qkv_0.view(3, B, _L, C//2)
qkv_1 = torch.roll(qkv[:,:,:,:,C//2:], shifts=(-self.shift_size[1], -self.shift_size[0]), dims=(2, 3))
qkv_1 = qkv_1.view(3, B, _L, C//2)
if self.patches_resolution != _H or self.patches_resolution != _W:
mask_tmp = self.calculate_mask(_H, _W)
x1_shift = self.attns[0](qkv_0, _H, _W, mask=mask_tmp[0].to(x.device))
x2_shift = self.attns[1](qkv_1, _H, _W, mask=mask_tmp[1].to(x.device))
else:
x1_shift = self.attns[0](qkv_0, _H, _W, mask=self.attn_mask_0)
x2_shift = self.attns[1](qkv_1, _H, _W, mask=self.attn_mask_1)
x1 = torch.roll(x1_shift, shifts=(self.shift_size[0], self.shift_size[1]), dims=(1, 2))
x2 = torch.roll(x2_shift, shifts=(self.shift_size[1], self.shift_size[0]), dims=(1, 2))
x1 = x1[:, :H, :W, :].reshape(B, L, C//2)
x2 = x2[:, :H, :W, :].reshape(B, L, C//2)
# attention output
attened_x = torch.cat([x1,x2], dim=2)
else:
x1 = self.attns[0](qkv[:,:,:,:C//2], _H, _W)[:, :H, :W, :].reshape(B, L, C//2)
x2 = self.attns[1](qkv[:,:,:,C//2:], _H, _W)[:, :H, :W, :].reshape(B, L, C//2)
# attention output
attened_x = torch.cat([x1,x2], dim=2)
# convolution output
conv_x = self.dwconv(v)
# Adaptive Interaction Module (AIM)
# C-Map (before sigmoid)
channel_map = self.channel_interaction(conv_x).permute(0, 2, 3, 1).contiguous().view(B, 1, C)
# S-Map (before sigmoid)
attention_reshape = attened_x.transpose(-2,-1).contiguous().view(B, C, H, W)
spatial_map = self.spatial_interaction(attention_reshape)
# C-I
attened_x = attened_x * torch.sigmoid(channel_map)
# S-I
conv_x = torch.sigmoid(spatial_map) * conv_x
conv_x = conv_x.permute(0, 2, 3, 1).contiguous().view(B, L, C)
x = attened_x + conv_x
x = self.proj(x)
x = self.proj_drop(x)
return x
class Adaptive_Channel_Attention(nn.Module):
# The implementation builds on XCiT code https://github.com/facebookresearch/xcit
""" Adaptive Channel Self-Attention
Args:
dim (int): Number of input channels.
num_heads (int): Number of attention heads. Default: 6
qkv_bias (bool): If True, add a learnable bias to query, key, value. Default: True
qk_scale (float | None): Override default qk scale of head_dim ** -0.5 if set.
attn_drop (float): Attention dropout rate. Default: 0.0
drop_path (float): Stochastic depth rate. Default: 0.0
"""
def __init__(self, dim, num_heads=8, qkv_bias=False, qk_scale=None, attn_drop=0., proj_drop=0.):
super().__init__()
self.num_heads = num_heads
self.temperature = nn.Parameter(torch.ones(num_heads, 1, 1))
self.qkv = nn.Linear(dim, dim * 3, bias=qkv_bias)
self.attn_drop = nn.Dropout(attn_drop)
self.proj = nn.Linear(dim, dim)
self.proj_drop = nn.Dropout(proj_drop)
self.dwconv = nn.Sequential(
nn.Conv2d(dim, dim, kernel_size=3, stride=1, padding=1,groups=dim),
nn.BatchNorm2d(dim),
nn.GELU()
)
self.channel_interaction = nn.Sequential(
nn.AdaptiveAvgPool2d(1),
nn.Conv2d(dim, dim // 8, kernel_size=1),
nn.BatchNorm2d(dim // 8),
nn.GELU(),
nn.Conv2d(dim // 8, dim, kernel_size=1),
)
self.spatial_interaction = nn.Sequential(
nn.Conv2d(dim, dim // 16, kernel_size=1),
nn.BatchNorm2d(dim // 16),
nn.GELU(),
nn.Conv2d(dim // 16, 1, kernel_size=1)
)
def forward(self, x, H, W):
"""
Input: x: (B, H*W, C), H, W
Output: x: (B, H*W, C)
"""
B, N, C = x.shape
qkv = self.qkv(x).reshape(B, N, 3, self.num_heads, C // self.num_heads)
qkv = qkv.permute(2, 0, 3, 1, 4)
q, k, v = qkv[0], qkv[1], qkv[2]
q = q.transpose(-2, -1)
k = k.transpose(-2, -1)
v = v.transpose(-2, -1)
v_ = v.reshape(B, C, N).contiguous().view(B, C, H, W)
q = torch.nn.functional.normalize(q, dim=-1)
k = torch.nn.functional.normalize(k, dim=-1)
attn = (q @ k.transpose(-2, -1)) * self.temperature
attn = attn.softmax(dim=-1)
attn = self.attn_drop(attn)
# attention output
attened_x = (attn @ v).permute(0, 3, 1, 2).reshape(B, N, C)
# convolution output
conv_x = self.dwconv(v_)
# Adaptive Interaction Module (AIM)
# C-Map (before sigmoid)
attention_reshape = attened_x.transpose(-2,-1).contiguous().view(B, C, H, W)
channel_map = self.channel_interaction(attention_reshape)
# S-Map (before sigmoid)
spatial_map = self.spatial_interaction(conv_x).permute(0, 2, 3, 1).contiguous().view(B, N, 1)
# S-I
attened_x = attened_x * torch.sigmoid(spatial_map)
# C-I
conv_x = conv_x * torch.sigmoid(channel_map)
conv_x = conv_x.permute(0, 2, 3, 1).contiguous().view(B, N, C)
x = attened_x + conv_x
x = self.proj(x)
x = self.proj_drop(x)
return x
class DATB(nn.Module):
def __init__(self, dim, num_heads, reso=64, split_size=[2,4],shift_size=[1,2], expansion_factor=4., qkv_bias=False, qk_scale=None, drop=0.,
attn_drop=0., drop_path=0., act_layer=nn.GELU, norm_layer=nn.LayerNorm, rg_idx=0, b_idx=0):
super().__init__()
self.norm1 = norm_layer(dim)
if b_idx % 2 == 0:
# DSTB
self.attn = Adaptive_Spatial_Attention(
dim, num_heads=num_heads, reso=reso, split_size=split_size, shift_size=shift_size, qkv_bias=qkv_bias, qk_scale=qk_scale,
drop=drop, attn_drop=attn_drop, rg_idx=rg_idx, b_idx=b_idx
)
else:
# DCTB
self.attn = Adaptive_Channel_Attention(
dim, num_heads=num_heads, qkv_bias=qkv_bias, qk_scale=qk_scale, attn_drop=attn_drop,
proj_drop=drop
)
self.drop_path = DropPath(drop_path) if drop_path > 0. else nn.Identity()
ffn_hidden_dim = int(dim * expansion_factor)
self.ffn = SGFN(in_features=dim, hidden_features=ffn_hidden_dim, out_features=dim, act_layer=act_layer)
self.norm2 = norm_layer(dim)
def forward(self, x, x_size):
"""
Input: x: (B, H*W, C), x_size: (H, W)
Output: x: (B, H*W, C)
"""
H , W = x_size
x = x + self.drop_path(self.attn(self.norm1(x), H, W))
x = x + self.drop_path(self.ffn(self.norm2(x), H, W))
return x
class ResidualGroup(nn.Module):
""" ResidualGroup
Args:
dim (int): Number of input channels.
reso (int): Input resolution.
num_heads (int): Number of attention heads.
split_size (tuple(int)): Height and Width of spatial window.
expansion_factor (float): Ratio of ffn hidden dim to embedding dim.
qkv_bias (bool): If True, add a learnable bias to query, key, value. Default: True
qk_scale (float | None): Override default qk scale of head_dim ** -0.5 if set. Default: None
drop (float): Dropout rate. Default: 0
attn_drop(float): Attention dropout rate. Default: 0
drop_paths (float | None): Stochastic depth rate.
act_layer (nn.Module): Activation layer. Default: nn.GELU
norm_layer (nn.Module): Normalization layer. Default: nn.LayerNorm
depth (int): Number of dual aggregation Transformer blocks in residual group.
use_chk (bool): Whether to use checkpointing to save memory.
resi_connection: The convolutional block before residual connection. '1conv'/'3conv'
"""
def __init__( self,
dim,
reso,
num_heads,
split_size=[2,4],
expansion_factor=4.,
qkv_bias=False,
qk_scale=None,
drop=0.,
attn_drop=0.,
drop_paths=None,
act_layer=nn.GELU,
norm_layer=nn.LayerNorm,
depth=2,
use_chk=False,
resi_connection='1conv',
rg_idx=0):
super().__init__()
self.use_chk = use_chk
self.reso = reso
self.blocks = nn.ModuleList([
DATB(
dim=dim,
num_heads=num_heads,
reso = reso,
split_size = split_size,
shift_size = [split_size[0]//2, split_size[1]//2],
expansion_factor=expansion_factor,
qkv_bias=qkv_bias,
qk_scale=qk_scale,
drop=drop,
attn_drop=attn_drop,
drop_path=drop_paths[i],
act_layer=act_layer,
norm_layer=norm_layer,
rg_idx = rg_idx,
b_idx = i,
)for i in range(depth)])
if resi_connection == '1conv':
self.conv = nn.Conv2d(dim, dim, 3, 1, 1)
elif resi_connection == '3conv':
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))
def forward(self, x, x_size):
"""
Input: x: (B, H*W, C), x_size: (H, W)
Output: x: (B, H*W, C)
"""
H, W = x_size
res = x
for blk in self.blocks:
if self.use_chk:
x = checkpoint.checkpoint(blk, x, x_size)
else:
x = blk(x, x_size)
x = rearrange(x, "b (h w) c -> b c h w", h=H, w=W)
x = self.conv(x)
x = rearrange(x, "b c h w -> b (h w) c")
x = res + x
return x
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
flops = h * w * self.num_feat * 3 * 9
return flops
class DAT(nn.Module):
""" Dual Aggregation Transformer
Args:
img_size (int): Input image size. Default: 64
in_chans (int): Number of input image channels. Default: 3
embed_dim (int): Patch embedding dimension. Default: 180
depths (tuple(int)): Depth of each residual group (number of DATB in each RG).
split_size (tuple(int)): Height and Width of spatial window.
num_heads (tuple(int)): Number of attention heads in different residual groups.
expansion_factor (float): Ratio of ffn 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 | None): 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
act_layer (nn.Module): Activation layer. Default: nn.GELU
norm_layer (nn.Module): Normalization layer. Default: nn.LayerNorm
use_chk (bool): Whether to use checkpointing to save memory.
upscale: Upscale factor. 2/3/4 for image SR
img_range: Image range. 1. or 255.
resi_connection: The convolutional block before residual connection. '1conv'/'3conv'
"""
def __init__(self,
img_size=64,
in_chans=3,
embed_dim=180,
split_size=[2,4],
depth=[2,2,2,2],
num_heads=[2,2,2,2],
expansion_factor=4.,
qkv_bias=True,
qk_scale=None,
drop_rate=0.,
attn_drop_rate=0.,
drop_path_rate=0.1,
act_layer=nn.GELU,
norm_layer=nn.LayerNorm,
use_chk=False,
upscale=2,
img_range=1.,
resi_connection='1conv',
upsampler='pixelshuffle',
**kwargs):
super().__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
# ------------------------- 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(depth)
self.use_chk = use_chk
self.num_features = self.embed_dim = embed_dim # num_features for consistency with other models
heads=num_heads
self.before_RG = nn.Sequential(
Rearrange('b c h w -> b (h w) c'),
nn.LayerNorm(embed_dim)
)
curr_dim = embed_dim
dpr = [x.item() for x in torch.linspace(0, drop_path_rate, np.sum(depth))] # stochastic depth decay rule
self.layers = nn.ModuleList()
for i in range(self.num_layers):
layer = ResidualGroup(
dim=embed_dim,
num_heads=heads[i],
reso=img_size,
split_size=split_size,
expansion_factor=expansion_factor,
qkv_bias=qkv_bias,
qk_scale=qk_scale,
drop=drop_rate,
attn_drop=attn_drop_rate,
drop_paths=dpr[sum(depth[:i]):sum(depth[:i + 1])],
act_layer=act_layer,
norm_layer=norm_layer,
depth=depth[i],
use_chk=use_chk,
resi_connection=resi_connection,
rg_idx=i)
self.layers.append(layer)
self.norm = norm_layer(curr_dim)
# 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, 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,
(img_size, img_size))
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.BatchNorm2d, nn.GroupNorm, nn.InstanceNorm2d)):
nn.init.constant_(m.bias, 0)
nn.init.constant_(m.weight, 1.0)
def forward_features(self, x):
_, _, H, W = x.shape
x_size = [H, W]
x = self.before_RG(x)
for layer in self.layers:
x = layer(x, x_size)
x = self.norm(x)
x = rearrange(x, "b (h w) c -> b c h w", h=H, w=W)
return x
def forward(self, x):
"""
Input: x: (B, C, H, W)
"""
self.mean = self.mean.type_as(x)
x = (x - self.mean) * self.img_range
if self.upsampler == 'pixelshuffle':
# for image 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)
x = x / self.img_range + self.mean
return x
if __name__ == '__main__':
upscale = 1
height = 64
width = 64
model = DAT(upscale=4,
in_chans=3,
img_size=64,
img_range=1.,
depth=[18],
embed_dim=60,
num_heads=[6],
expansion_factor=2,
resi_connection='3conv',
split_size=[8,32],
upsampler='pixelshuffledirect',
).cuda().eval()
print(height, width)
x = torch.randn((1, 3, height, width)).cuda()
x = model(x)
print(x.shape)