From 9cc7dda6e5fcbbc7ac5ba5d2d44050d2a8e3e38d Mon Sep 17 00:00:00 2001 From: Ross Wightman Date: Thu, 29 Apr 2021 21:08:37 -0700 Subject: [PATCH] Fixup byoanet configs to pass unit tests. Add swin_attn and swinnet26t model for testing. --- timm/models/byoanet.py | 40 +++++- timm/models/layers/create_self_attn.py | 5 + timm/models/layers/swin_attn.py | 178 +++++++++++++++++++++++++ 3 files changed, 216 insertions(+), 7 deletions(-) create mode 100644 timm/models/layers/swin_attn.py diff --git a/timm/models/byoanet.py b/timm/models/byoanet.py index ca46043f..df88535d 100644 --- a/timm/models/byoanet.py +++ b/timm/models/byoanet.py @@ -35,7 +35,7 @@ __all__ = ['ByoaNet'] def _cfg(url='', **kwargs): return { 'url': url, 'num_classes': 1000, 'input_size': (3, 224, 224), 'pool_size': (7, 7), - 'crop_pct': 0.875, 'interpolation': 'bilinear', + 'crop_pct': 0.875, 'interpolation': 'bicubic', 'mean': IMAGENET_DEFAULT_MEAN, 'std': IMAGENET_DEFAULT_STD, 'first_conv': 'stem.conv1.conv', 'classifier': 'head.fc', 'fixed_input_size': False, 'min_input_size': (3, 224, 224), @@ -45,17 +45,19 @@ def _cfg(url='', **kwargs): default_cfgs = { # GPU-Efficient (ResNet) weights - 'botnet26t_256': _cfg(url='', fixed_input_size=True, input_size=(3, 256, 256)), + 'botnet26t_256': _cfg(url='', fixed_input_size=True, input_size=(3, 256, 256), pool_size=(8, 8)), 'botnet50t_224': _cfg(url='', fixed_input_size=True), 'botnet50t_c4c5_224': _cfg(url='', fixed_input_size=True), 'halonet_h1': _cfg(url='', input_size=(3, 256, 256), pool_size=(8, 8), min_input_size=(3, 256, 256)), 'halonet_h1_c4c5': _cfg(url='', input_size=(3, 256, 256), pool_size=(8, 8), min_input_size=(3, 256, 256)), - 'halonet26t': _cfg(url='', input_size=(3, 256, 256)), - 'halonet50t': _cfg(url=''), + 'halonet26t': _cfg(url='', input_size=(3, 256, 256), pool_size=(8, 8), min_input_size=(3, 256, 256)), + 'halonet50t': _cfg(url='', min_input_size=(3, 224, 224)), - 'lambda_resnet26t': _cfg(url='', min_input_size=(3, 128, 128), input_size=(3, 256, 256)), + 'lambda_resnet26t': _cfg(url='', min_input_size=(3, 128, 128), input_size=(3, 256, 256), pool_size=(8, 8)), 'lambda_resnet50t': _cfg(url='', min_input_size=(3, 128, 128)), + + 'swinnet26t_256': _cfg(url='', fixed_input_size=True, input_size=(3, 256, 256), pool_size=(8, 8)), } @@ -95,10 +97,10 @@ model_cfgs = dict( botnet26t=ByoaCfg( blocks=( - ByoaBlocksCfg(type='bottle', d=3, c=256, s=2, gs=0, br=0.25), + ByoaBlocksCfg(type='bottle', d=3, c=256, s=1, gs=0, br=0.25), ByoaBlocksCfg(type='bottle', d=4, c=512, s=2, gs=0, br=0.25), interleave_attn(types=('bottle', 'self_attn'), every=1, d=2, c=1024, s=2, gs=0, br=0.25), - ByoaBlocksCfg(type='self_attn', d=3, c=2048, s=1, gs=0, br=0.25), + ByoaBlocksCfg(type='self_attn', d=3, c=2048, s=2, gs=0, br=0.25), ), stem_chs=64, stem_type='tiered', @@ -230,6 +232,22 @@ model_cfgs = dict( self_attn_layer='lambda', self_attn_kwargs=dict() ), + + swinnet26t=ByoaCfg( + blocks=( + ByoaBlocksCfg(type='bottle', d=3, c=256, s=1, gs=0, br=0.25), + ByoaBlocksCfg(type='bottle', d=4, c=512, s=2, gs=0, br=0.25), + interleave_attn(types=('bottle', 'self_attn'), every=1, d=2, c=1024, s=2, gs=0, br=0.25), + ByoaBlocksCfg(type='self_attn', d=3, c=2048, s=2, gs=0, br=0.25), + ), + stem_chs=64, + stem_type='tiered', + stem_pool='maxpool', + num_features=0, + self_attn_layer='swin', + self_attn_fixed_size=True, + self_attn_kwargs=dict(win_size=8) + ), ) @@ -452,3 +470,11 @@ def lambda_resnet50t(pretrained=False, **kwargs): """ Lambda-ResNet-50T. Lambda layers in one C4 stage and all C5. """ return _create_byoanet('lambda_resnet50t', pretrained=pretrained, **kwargs) + + +@register_model +def swinnet26t_256(pretrained=False, **kwargs): + """ + """ + kwargs.setdefault('img_size', 256) + return _create_byoanet('swinnet26t_256', 'swinnet26t', pretrained=pretrained, **kwargs) diff --git a/timm/models/layers/create_self_attn.py b/timm/models/layers/create_self_attn.py index 8c0984c8..ba208f17 100644 --- a/timm/models/layers/create_self_attn.py +++ b/timm/models/layers/create_self_attn.py @@ -1,6 +1,7 @@ from .bottleneck_attn import BottleneckAttn from .halo_attn import HaloAttn from .lambda_layer import LambdaLayer +from .swin_attn import WindowAttention def get_self_attn(attn_type): @@ -10,6 +11,10 @@ def get_self_attn(attn_type): return HaloAttn elif attn_type == 'lambda': return LambdaLayer + elif attn_type == 'swin': + return WindowAttention + else: + assert False, f"Unknown attn type ({attn_type})" def create_self_attn(attn_type, dim, stride=1, **kwargs): diff --git a/timm/models/layers/swin_attn.py b/timm/models/layers/swin_attn.py new file mode 100644 index 00000000..46dacb62 --- /dev/null +++ b/timm/models/layers/swin_attn.py @@ -0,0 +1,178 @@ +""" Shifted Window Attn + +This is a WIP experiment to apply windowed attention from the Swin Transformer +to a stand-alone module for use as an attn block in conv nets. + +Based on original swin window code at https://github.com/microsoft/Swin-Transformer +Swin Transformer paper: https://arxiv.org/pdf/2103.14030.pdf +""" +from typing import Optional + +import torch +import torch.nn as nn + +from .drop import DropPath +from .helpers import to_2tuple +from .weight_init import trunc_normal_ + + +def window_partition(x, win_size: int): + """ + Args: + x: (B, H, W, C) + win_size (int): window size + + Returns: + windows: (num_windows*B, window_size, window_size, C) + """ + B, H, W, C = x.shape + x = x.view(B, H // win_size, win_size, W // win_size, win_size, C) + windows = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(-1, win_size, win_size, C) + return windows + + +def window_reverse(windows, win_size: int, H: int, W: int): + """ + Args: + windows: (num_windows*B, window_size, window_size, C) + win_size (int): Window size + H (int): Height of image + W (int): Width of image + + Returns: + x: (B, H, W, C) + """ + B = int(windows.shape[0] / (H * W / win_size / win_size)) + x = windows.view(B, H // win_size, W // win_size, win_size, win_size, -1) + x = x.permute(0, 1, 3, 2, 4, 5).contiguous().view(B, H, W, -1) + return x + + +class WindowAttention(nn.Module): + r""" Window based multi-head self attention (W-MSA) module with relative position bias. + It supports both of shifted and non-shifted window. + + Args: + dim (int): Number of input channels. + win_size (int): The height and width of the window. + num_heads (int): Number of attention heads. + qkv_bias (bool, optional): If True, add a learnable bias to query, key, value. Default: True + attn_drop (float, optional): Dropout ratio of attention weight. Default: 0.0 + """ + + def __init__( + self, dim, dim_out=None, feat_size=None, stride=1, win_size=8, shift_size=None, num_heads=8, + qkv_bias=True, attn_drop=0.): + + super().__init__() + self.dim_out = dim_out or dim + self.feat_size = to_2tuple(feat_size) + self.win_size = win_size + self.shift_size = shift_size or win_size // 2 + if min(self.feat_size) <= win_size: + # if window size is larger than input resolution, we don't partition windows + self.shift_size = 0 + self.win_size = min(self.feat_size) + assert 0 <= self.shift_size < self.win_size, "shift_size must in 0-window_size" + self.num_heads = num_heads + head_dim = self.dim_out // num_heads + self.scale = head_dim ** -0.5 + + if self.shift_size > 0: + # calculate attention mask for SW-MSA + H, W = self.feat_size + img_mask = torch.zeros((1, H, W, 1)) # 1 H W 1 + h_slices = ( + slice(0, -self.win_size), + slice(-self.win_size, -self.shift_size), + slice(-self.shift_size, None)) + w_slices = ( + slice(0, -self.win_size), + slice(-self.win_size, -self.shift_size), + slice(-self.shift_size, None)) + cnt = 0 + for h in h_slices: + for w in w_slices: + img_mask[:, h, w, :] = cnt + cnt += 1 + mask_windows = window_partition(img_mask, self.win_size) # num_win, window_size, window_size, 1 + mask_windows = mask_windows.view(-1, self.win_size * self.win_size) + attn_mask = mask_windows.unsqueeze(1) - mask_windows.unsqueeze(2) + attn_mask = attn_mask.masked_fill(attn_mask != 0, float(-100.0)).masked_fill(attn_mask == 0, float(0.0)) + else: + attn_mask = None + self.register_buffer("attn_mask", attn_mask) + + # define a parameter table of relative position bias + self.relative_position_bias_table = nn.Parameter( + # 2 * Wh - 1 * 2 * Ww - 1, nH + torch.zeros((2 * self.win_size - 1) * (2 * self.win_size - 1), num_heads)) + + # get pair-wise relative position index for each token inside the window + coords_h = torch.arange(self.win_size) + coords_w = torch.arange(self.win_size) + coords = torch.stack(torch.meshgrid([coords_h, coords_w])) # 2, Wh, Ww + coords_flatten = torch.flatten(coords, 1) # 2, Wh*Ww + relative_coords = coords_flatten[:, :, None] - coords_flatten[:, None, :] # 2, Wh*Ww, Wh*Ww + relative_coords = relative_coords.permute(1, 2, 0).contiguous() # Wh*Ww, Wh*Ww, 2 + relative_coords[:, :, 0] += self.win_size - 1 # shift to start from 0 + relative_coords[:, :, 1] += self.win_size - 1 + relative_coords[:, :, 0] *= 2 * self.win_size - 1 + relative_position_index = relative_coords.sum(-1) # Wh*Ww, Wh*Ww + self.register_buffer("relative_position_index", relative_position_index) + trunc_normal_(self.relative_position_bias_table, std=.02) + + self.qkv = nn.Linear(dim, self.dim_out * 3, bias=qkv_bias) + self.attn_drop = nn.Dropout(attn_drop) + self.softmax = nn.Softmax(dim=-1) + self.pool = nn.AvgPool2d(2, 2) if stride == 2 else nn.Identity() + + def forward(self, x): + B, C, H, W = x.shape + x = x.permute(0, 2, 3, 1) + + # 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 + + # partition windows + win_size_sq = self.win_size * self.win_size + x_windows = window_partition(shifted_x, self.win_size) # num_win * B, window_size, window_size, C + x_windows = x_windows.view(-1, win_size_sq, C) # num_win * B, window_size*window_size, C + BW, N, _ = x_windows.shape + + qkv = self.qkv(x_windows) + qkv = qkv.reshape(BW, N, 3, self.num_heads, self.dim_out // self.num_heads).permute(2, 0, 3, 1, 4) + q, k, v = qkv[0], qkv[1], qkv[2] + q = q * self.scale + attn = (q @ k.transpose(-2, -1)) + + relative_position_bias = self.relative_position_bias_table[ + self.relative_position_index.view(-1)].view(win_size_sq, win_size_sq, -1) + relative_position_bias = relative_position_bias.permute(2, 0, 1).contiguous() # nH, Wh * Ww, Wh * Ww + attn = attn + relative_position_bias.unsqueeze(0) + if self.attn_mask is not None: + num_win = self.attn_mask.shape[0] + attn = attn.view(B, num_win, self.num_heads, N, N) + self.attn_mask.unsqueeze(1).unsqueeze(0) + attn = attn.view(-1, self.num_heads, N, N) + attn = self.softmax(attn) + attn = self.attn_drop(attn) + + x = (attn @ v).transpose(1, 2).reshape(BW, N, self.dim_out) + + # merge windows + x = x.view(-1, self.win_size, self.win_size, self.dim_out) + shifted_x = window_reverse(x, self.win_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, self.dim_out).permute(0, 3, 1, 2) + x = self.pool(x) + return x + +