[Enhance] Enhance ArcFaceClsHead. (#1181)

* update arcface

* fix unit tests

* add adv-margins

add adv-margins

update arcface

* rebase

* update doc and fix ut

* rebase

* update code

* rebase

* use label data

* update set-margins

* Modify Arcface related method names.

Co-authored-by: mzr1996 <[email protected]>

docs/en/api/engine.rst

@@ -31,7 +31,8 @@ Hooks
    ClassNumCheckHook
    PreciseBNHook
    VisualizationHook
-   SwitchRecipeHook
+   PrepareProtoBeforeValLoopHook
+   SetAdaptiveMarginsHook
 
 .. module:: mmcls.engine.optimizers
 

docs/en/api/models.rst

@@ -140,6 +140,7 @@ Heads
    EfficientFormerClsHead
    DeiTClsHead
    ConformerHead
+   ArcFaceClsHead
    MultiLabelClsHead
    MultiLabelLinearClsHead
    CSRAClsHead

mmcls/engine/hooks/__init__.py

@@ -1,11 +1,13 @@
 # Copyright (c) OpenMMLab. All rights reserved.
 from .class_num_check_hook import ClassNumCheckHook
+from .margin_head_hooks import SetAdaptiveMarginsHook
 from .precise_bn_hook import PreciseBNHook
 from .retriever_hooks import PrepareProtoBeforeValLoopHook
 from .switch_recipe_hook import SwitchRecipeHook
 from .visualization_hook import VisualizationHook
 
 __all__ = [
     'ClassNumCheckHook', 'PreciseBNHook', 'VisualizationHook',
-    'SwitchRecipeHook', 'PrepareProtoBeforeValLoopHook'
+    'SwitchRecipeHook', 'PrepareProtoBeforeValLoopHook',
+    'SetAdaptiveMarginsHook'
 ]

mmcls/engine/hooks/margin_head_hooks.py

@@ -0,0 +1,61 @@
+# Copyright (c) OpenMMLab. All rights reserved
+import numpy as np
+from mmengine.hooks import Hook
+from mmengine.model import is_model_wrapper
+
+from mmcls.models.heads import ArcFaceClsHead
+from mmcls.registry import HOOKS
+
+
+@HOOKS.register_module()
+class SetAdaptiveMarginsHook(Hook):
+    r"""Set adaptive-margins in ArcFaceClsHead based on the power of
+    category-wise count.
+
+    A PyTorch implementation of paper `Google Landmark Recognition 2020
+    Competition Third Place Solution <https://arxiv.org/abs/2010.05350>`_.
+    The margins will be
+    :math:`\text{f}(n) = (marginMax - marginMin) · norm(n^p) + marginMin`.
+    The `n` indicates the number of occurrences of a category.
+
+    Args:
+        margin_min (float): Lower bound of margins. Defaults to 0.05.
+        margin_max (float): Upper bound of margins. Defaults to 0.5.
+        power (float): The power of category freqercy. Defaults to -0.25.
+    """
+
+    def __init__(self, margin_min=0.05, margin_max=0.5, power=-0.25) -> None:
+        self.margin_min = margin_min
+        self.margin_max = margin_max
+        self.margin_range = margin_max - margin_min
+        self.p = power
+
+    def before_train(self, runner):
+        """change the margins in ArcFaceClsHead.
+
+        Args:
+            runner (obj: `Runner`): Runner.
+        """
+        model = runner.model
+        if is_model_wrapper(model):
+            model = model.module
+
+        if (hasattr(model, 'head')
+                and not isinstance(model.head, ArcFaceClsHead)):
+            raise ValueError(
+                'Hook ``SetFreqPowAdvMarginsHook`` could only be used '
+                f'for ``ArcFaceClsHead``, but get {type(model.head)}')
+
+        # generate margins base on the dataset.
+        gt_labels = runner.train_dataloader.dataset.get_gt_labels()
+        label_count = np.bincount(gt_labels)
+        label_count[label_count == 0] = 1  # At least one occurrence
+        pow_freq = np.power(label_count, self.p)
+
+        min_f, max_f = pow_freq.min(), pow_freq.max()
+        normized_pow_freq = (pow_freq - min_f) / (max_f - min_f)
+        margins = normized_pow_freq * self.margin_range + self.margin_min
+
+        assert len(margins) == runner.model.head.num_classes
+
+        model.head.set_margins(margins)

mmcls/models/backbones/hornet.py

@@ -250,20 +250,24 @@ def forward(self, x):
 
 @MODELS.register_module()
 class HorNet(BaseBackbone):
-    """HorNet
-    A PyTorch impl of : `HorNet: Efficient High-Order Spatial Interactions
-    with Recursive Gated Convolutions`
-    Inspiration from
-    https://github.com/raoyongming/HorNet
+    """HorNet.
+
+    A PyTorch implementation of paper `HorNet: Efficient High-Order Spatial
+    Interactions with Recursive Gated Convolutions
+    <https://arxiv.org/abs/2207.14284>`_ .
+    Inspiration from https://github.com/raoyongming/HorNet
+
     Args:
         arch (str | dict): HorNet architecture.
+
             If use string, choose from 'tiny', 'small', 'base' and 'large'.
             If use dict, it should have below keys:
             - **base_dim** (int): The base dimensions of embedding.
             - **depths** (List[int]): The number of blocks in each stage.
             - **orders** (List[int]): The number of order of gnConv in each
                 stage.
             - **dw_cfg** (List[dict]): The Config for dw conv.
+
             Defaults to 'tiny'.
         in_channels (int): Number of input image channels. Defaults to 3.
         drop_path_rate (float): Stochastic depth rate. Defaults to 0.

mmcls/models/heads/__init__.py

@@ -1,10 +1,10 @@
 # Copyright (c) OpenMMLab. All rights reserved.
-from .arcface_head import ArcFaceClsHead
 from .cls_head import ClsHead
 from .conformer_head import ConformerHead
 from .deit_head import DeiTClsHead
 from .efficientformer_head import EfficientFormerClsHead
 from .linear_head import LinearClsHead
+from .margin_head import ArcFaceClsHead
 from .multi_label_cls_head import MultiLabelClsHead
 from .multi_label_csra_head import CSRAClsHead
 from .multi_label_linear_head import MultiLabelLinearClsHead