add starnet

brianhou0208 · brianhou0208 · commit b60a4fb329b3 · 2025-04-29T05:38:42.000+08:00
diff --git a/timm/models/__init__.py b/timm/models/__init__.py
@@ -61,6 +61,7 @@
 from .senet import *
 from .sequencer import *
 from .sknet import *
+from .starnet import *
 from .swiftformer import *
 from .swin_transformer import *
 from .swin_transformer_v2 import *
diff --git a/timm/models/starnet.py b/timm/models/starnet.py
@@ -0,0 +1,344 @@
+"""
+Implementation of Prof-of-Concept Network: StarNet.
+
+We make StarNet as simple as possible [to show the key contribution of element-wise multiplication]:
+    - like NO layer-scale in network design,
+    - and NO EMA during training,
+    - which would improve the performance further.
+
+Created by: Xu Ma (Email: ma.xu1@northeastern.edu)
+Modified Date: Mar/29/2024
+"""
+from typing import Any, Dict, List, Optional, Set, Tuple, Union
+
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+
+from timm.data import IMAGENET_DEFAULT_MEAN, IMAGENET_DEFAULT_STD
+from timm.layers import DropPath, SelectAdaptivePool2d, Linear, LayerType, trunc_normal_
+from ._builder import build_model_with_cfg
+from ._features import feature_take_indices
+from ._manipulate import checkpoint_seq
+from ._registry import register_model, generate_default_cfgs
+
+__all__ = ['StarNet']
+
+
+class ConvBN(nn.Sequential):
+    def __init__(
+            self,
+            in_channels: int,
+            out_channels: int,
+            kernel_size: int = 1,
+            stride: int = 1,
+            padding: int = 0,
+            with_bn: bool = True,
+            **kwargs
+    ):
+        super().__init__()
+        self.add_module('conv', nn.Conv2d(
+            in_channels, out_channels, kernel_size, stride=stride, padding=padding, **kwargs))
+        if with_bn:
+            self.add_module('bn', nn.BatchNorm2d(out_channels))
+            nn.init.constant_(self.bn.weight, 1)
+            nn.init.constant_(self.bn.bias, 0)
+
+
+class Block(nn.Module):
+    def __init__(
+            self,
+            dim: int,
+            mlp_ratio: int = 3,
+            drop_path: float = 0.,
+            act_layer: LayerType = nn.ReLU6,
+    ):
+        super().__init__()
+        self.dwconv = ConvBN(dim, dim, 7, 1, 3, groups=dim, with_bn=True)
+        self.f1 = ConvBN(dim, mlp_ratio * dim, 1, with_bn=False)
+        self.f2 = ConvBN(dim, mlp_ratio * dim, 1, with_bn=False)
+        self.g = ConvBN(mlp_ratio * dim, dim, 1, with_bn=True)
+        self.dwconv2 = ConvBN(dim, dim, 7, 1, 3, groups=dim, with_bn=False)
+        self.act = act_layer()
+        self.drop_path = DropPath(drop_path) if drop_path > 0. else nn.Identity()
+
+    def forward(self, x: torch.Tensor) -> torch.Tensor:
+        residual = x
+        x = self.dwconv(x)
+        x1, x2 = self.f1(x), self.f2(x)
+        x = self.act(x1) * x2
+        x = self.dwconv2(self.g(x))
+        x = residual + self.drop_path(x)
+        return x
+
+
+class StarNet(nn.Module):
+    def __init__(
+            self,
+            base_dim: int = 32,
+            depths: List[int] = [3, 3, 12, 5],
+            mlp_ratio: int = 4,
+            drop_rate: float = 0.,
+            drop_path_rate: float = 0.,
+            act_layer: LayerType = nn.ReLU6,
+            num_classes: int = 1000,
+            in_chans: int = 3,
+            global_pool: str = 'avg',
+            output_stride: int = 32,
+            **kwargs,
+    ):
+        super().__init__()
+        assert output_stride == 32
+        self.num_classes = num_classes
+        self.drop_rate = drop_rate
+        self.grad_checkpointing = False
+        self.feature_info = []
+        stem_chs = 32
+        
+        # stem layer
+        self.stem = nn.Sequential(
+            ConvBN(in_chans, stem_chs, kernel_size=3, stride=2, padding=1), 
+            act_layer(),
+        )
+        prev_chs = stem_chs
+
+        # build stages
+        dpr = [x.item() for x in torch.linspace(0, drop_path_rate, sum(depths))] # stochastic depth
+        stages = []
+        cur = 0
+        for i_layer in range(len(depths)):
+            embed_dim = base_dim * 2 ** i_layer
+            down_sampler = ConvBN(prev_chs, embed_dim, 3, stride=2, padding=1)
+            blocks = [Block(embed_dim, mlp_ratio, dpr[cur + i], act_layer) for i in range(depths[i_layer])]
+            cur += depths[i_layer]
+            prev_chs = embed_dim
+            stages.append(nn.Sequential(down_sampler, *blocks))
+            self.feature_info.append(dict(
+                    num_chs=prev_chs, reduction=2**(i_layer+2), module=f'stages.{i_layer}'))
+        self.stages = nn.Sequential(*stages)
+        # head
+        self.num_features = self.head_hidden_size = prev_chs
+        self.norm = nn.BatchNorm2d(self.num_features)
+        self.global_pool = SelectAdaptivePool2d(pool_type=global_pool)
+        self.flatten = nn.Flatten(1) if global_pool else nn.Identity()  # don't flatten if pooling disabled
+        self.head = Linear(self.num_features, num_classes) if num_classes > 0 else nn.Identity()
+        self.apply(self._init_weights)
+
+    def _init_weights(self, m):
+        if isinstance(m, (nn.Linear, nn.Conv2d)):
+            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.BatchNorm2d):
+            nn.init.constant_(m.bias, 0)
+            nn.init.constant_(m.weight, 1.0)
+
+    @torch.jit.ignore
+    def no_weight_decay(self) -> Set:
+        return set()
+
+    @torch.jit.ignore
+    def group_matcher(self, coarse: bool = False) -> Dict[str, Any]:
+        matcher = dict(
+            stem=r'^stem\.\d+',
+            blocks=[(r'^stages\.(\d+)', None), (r'^norm', (99999,))]
+        )
+        return matcher
+
+    @torch.jit.ignore
+    def set_grad_checkpointing(self, enable: bool = True):
+        self.grad_checkpointing = enable
+
+    @torch.jit.ignore
+    def get_classifier(self) -> nn.Module:
+        return self.head
+
+    def reset_classifier(self, num_classes: int, global_pool: Optional[str] = None):
+        self.num_classes = num_classes
+        if global_pool is not None:
+            # NOTE: cannot meaningfully change pooling of efficient head after creation
+            self.global_pool = SelectAdaptivePool2d(pool_type=global_pool)
+            self.flatten = nn.Flatten(1) if global_pool else nn.Identity()  # don't flatten if pooling disabled
+        self.head = Linear(self.head_hidden_size, num_classes) if num_classes > 0 else nn.Identity()
+
+    def forward_intermediates(
+            self,
+            x: torch.Tensor,
+            indices: Optional[Union[int, List[int]]] = None,
+            norm: bool = False,
+            stop_early: bool = False,
+            output_fmt: str = 'NCHW',
+            intermediates_only: bool = False,
+    ) -> Union[List[torch.Tensor], Tuple[torch.Tensor, List[torch.Tensor]]]:
+        """ Forward features that returns intermediates.
+
+        Args:
+            x: Input image tensor
+            indices: Take last n blocks if int, all if None, select matching indices if sequence
+            norm: Apply norm layer to compatible intermediates
+            stop_early: Stop iterating over blocks when last desired intermediate hit
+            output_fmt: Shape of intermediate feature outputs
+            intermediates_only: Only return intermediate features
+        Returns:
+
+        """
+        assert output_fmt in ('NCHW',), 'Output shape must be NCHW.'
+        intermediates = []
+        take_indices, max_index = feature_take_indices(len(self.stages), indices)
+        last_idx = len(self.stages) - 1
+
+        # forward pass
+        x = self.stem(x)
+        if torch.jit.is_scripting() or not stop_early:  # can't slice blocks in torchscript
+            stages = self.stages
+        else:
+            stages = self.stages[:max_index + 1]
+
+        for feat_idx, stage in enumerate(stages):
+            x = stage(x)
+            if feat_idx in take_indices:
+                if norm and feat_idx == last_idx:
+                    x_inter = self.norm(x)  # applying final norm last intermediate
+                else:
+                    x_inter = x
+                intermediates.append(x_inter) 
+
+        if intermediates_only:
+            return intermediates
+
+        x = self.norm(x)
+
+        return x, intermediates
+
+    def prune_intermediate_layers(
+            self,
+            indices: Union[int, List[int]] = 1,
+            prune_norm: bool = False,
+            prune_head: bool = True,
+    ):
+        """ Prune layers not required for specified intermediates.
+        """
+        take_indices, max_index = feature_take_indices(len(self.stages), indices)
+        self.stages = self.stages[:max_index + 1]  # truncate blocks w/ stem as idx 0
+        if prune_norm:
+            self.norm = nn.Identity()
+        if prune_head:
+            self.reset_classifier(0, '')
+        return take_indices
+
+    def forward_features(self, x: torch.Tensor) -> torch.Tensor:
+        x = self.stem(x)
+        if self.grad_checkpointing and not torch.jit.is_scripting():
+            x = checkpoint_seq(self.stages, x, flatten=True)
+        else:
+            x = self.stages(x)
+        x = self.norm(x)
+        return x
+
+    def forward_head(self, x: torch.Tensor, pre_logits: bool = False) -> torch.Tensor:
+        x = self.global_pool(x)
+        x = self.flatten(x)
+        if self.drop_rate > 0.:
+            x = F.dropout(x, p=self.drop_rate, training=self.training)
+        return x if pre_logits else self.head(x)
+
+    def forward(self, x: torch.Tensor) -> torch.Tensor:
+        x = self.forward_features(x)
+        x = self.forward_head(x)
+        return x
+
+
+def checkpoint_filter_fn(state_dict: Dict[str, torch.Tensor], model: nn.Module) -> Dict[str, torch.Tensor]:
+    if 'state_dict' in state_dict:
+        state_dict = state_dict['state_dict']
+    out_dict = state_dict
+    return out_dict
+
+
+def _cfg(url: str = '', **kwargs: Any) -> Dict[str, Any]:
+    return {
+        'url': url, 'num_classes': 1000, 'input_size': (3, 224, 224), 'pool_size': (7, 7),
+        'crop_pct': 0.875, 'interpolation': 'bicubic',
+        'mean': IMAGENET_DEFAULT_MEAN, 'std': IMAGENET_DEFAULT_STD,
+        'first_conv': 'stem.0.conv', 'classifier': 'head',
+        'paper_ids': 'arXiv:2403.19967',
+        'paper_name': 'Rewrite the Stars',
+        'origin_url': 'https://github.com/ma-xu/Rewrite-the-Stars',
+        **kwargs
+    }
+
+
+default_cfgs = generate_default_cfgs({
+    'starnet_s1.in1k': _cfg(
+        # hf_hub_id='timm/',
+        url='https://github.com/ma-xu/Rewrite-the-Stars/releases/download/checkpoints_v1/starnet_s1.pth.tar',
+    ),
+    'starnet_s2.in1k': _cfg(
+        # hf_hub_id='timm/',
+        url='https://github.com/ma-xu/Rewrite-the-Stars/releases/download/checkpoints_v1/starnet_s2.pth.tar',
+    ),
+    'starnet_s3.in1k': _cfg(
+        # hf_hub_id='timm/',
+        url='https://github.com/ma-xu/Rewrite-the-Stars/releases/download/checkpoints_v1/starnet_s3.pth.tar',
+    ),
+    'starnet_s4.in1k': _cfg(
+        # hf_hub_id='timm/',
+        url='https://github.com/ma-xu/Rewrite-the-Stars/releases/download/checkpoints_v1/starnet_s4.pth.tar',
+    ),
+    'starnet_s050.untrained': _cfg(),
+    'starnet_s100.untrained': _cfg(),
+    'starnet_s150.untrained': _cfg(),
+})
+
+
+def _create_starnet(variant: str, pretrained: bool = False, **kwargs: Any) -> StarNet:
+    model = build_model_with_cfg(
+        StarNet, variant, pretrained,
+        pretrained_filter_fn=checkpoint_filter_fn,
+        feature_cfg=dict(out_indices=(0, 1, 2, 3), flatten_sequential=True),
+        **kwargs,
+    )
+    return model
+
+
+@register_model
+def starnet_s1(pretrained: bool = False, **kwargs: Any) -> StarNet:
+    model_args = dict(base_dim=24, depths=[2, 2, 8, 3])
+    return _create_starnet('starnet_s1', pretrained=pretrained, **dict(model_args, **kwargs))
+
+
+@register_model
+def starnet_s2(pretrained: bool = False, **kwargs: Any) -> StarNet:
+    model_args = dict(base_dim=32, depths=[1, 2, 6, 2])
+    return _create_starnet('starnet_s2', pretrained=pretrained, **dict(model_args, **kwargs))
+
+
+@register_model
+def starnet_s3(pretrained: bool = False, **kwargs: Any) -> StarNet:
+    model_args = dict(base_dim=32, depths=[2, 2, 8, 4])
+    return _create_starnet('starnet_s3', pretrained=pretrained, **dict(model_args, **kwargs))
+
+
+@register_model
+def starnet_s4(pretrained: bool = False, **kwargs: Any) -> StarNet:
+    model_args = dict(base_dim=32, depths=[3, 3, 12, 5])
+    return _create_starnet('starnet_s4', pretrained=pretrained, **dict(model_args, **kwargs))
+
+
+# very small networks #
+@register_model
+def starnet_s050(pretrained: bool = False, **kwargs: Any) -> StarNet:
+    model_args = dict(base_dim=16, depths=[1, 1, 3, 1], mlp_ratio=3)
+    return _create_starnet('starnet_s050', pretrained=pretrained, **dict(model_args, **kwargs))
+
+
+@register_model
+def starnet_s100(pretrained: bool = False, **kwargs: Any) -> StarNet:
+    model_args = dict(base_dim=20, depths=[1, 2, 4, 1], mlp_ratio=4)
+    return _create_starnet('starnet_s100', pretrained=pretrained, **dict(model_args, **kwargs))
+
+
+@register_model
+def starnet_s150(pretrained: bool = False, **kwargs: Any) -> StarNet:
+    model_args = dict(base_dim=24, depths=[1, 2, 4, 2], mlp_ratio=3)
+    return _create_starnet('starnet_s150', pretrained=pretrained, **dict(model_args, **kwargs))
