File size: 6,676 Bytes
cc0dd3c
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
# Copyright (c) OpenMMLab. All rights reserved.
from typing import Optional, Sequence, Tuple, Union

import numpy as np
import torch
from torch import Tensor, nn

from mmpose.evaluation.functional import keypoint_pck_accuracy
from mmpose.models.utils.tta import flip_coordinates
from mmpose.registry import KEYPOINT_CODECS, MODELS
from mmpose.utils.tensor_utils import to_numpy
from mmpose.utils.typing import (ConfigType, OptConfigType, OptSampleList,
                                 Predictions)
from ..base_head import BaseHead

OptIntSeq = Optional[Sequence[int]]


@MODELS.register_module()
class RLEHead(BaseHead):
    """Top-down regression head introduced in `RLE`_ by Li et al(2021). The
    head is composed of fully-connected layers to predict the coordinates and
    sigma(the variance of the coordinates) together.

    Args:
        in_channels (int | sequence[int]): Number of input channels
        num_joints (int): Number of joints
        loss (Config): Config for keypoint loss. Defaults to use
            :class:`RLELoss`
        decoder (Config, optional): The decoder config that controls decoding
            keypoint coordinates from the network output. Defaults to ``None``
        init_cfg (Config, optional): Config to control the initialization. See
            :attr:`default_init_cfg` for default settings

    .. _`RLE`: https://arxiv.org/abs/2107.11291
    """

    _version = 2

    def __init__(self,
                 in_channels: Union[int, Sequence[int]],
                 num_joints: int,
                 loss: ConfigType = dict(
                     type='RLELoss', use_target_weight=True),
                 decoder: OptConfigType = None,
                 init_cfg: OptConfigType = None):

        if init_cfg is None:
            init_cfg = self.default_init_cfg

        super().__init__(init_cfg)

        self.in_channels = in_channels
        self.num_joints = num_joints
        self.loss_module = MODELS.build(loss)
        if decoder is not None:
            self.decoder = KEYPOINT_CODECS.build(decoder)
        else:
            self.decoder = None

        # Define fully-connected layers
        self.fc = nn.Linear(in_channels, self.num_joints * 4)

        # Register the hook to automatically convert old version state dicts
        self._register_load_state_dict_pre_hook(self._load_state_dict_pre_hook)

    def forward(self, feats: Tuple[Tensor]) -> Tensor:
        """Forward the network. The input is multi scale feature maps and the
        output is the coordinates.

        Args:
            feats (Tuple[Tensor]): Multi scale feature maps.

        Returns:
            Tensor: output coordinates(and sigmas[optional]).
        """
        x = feats[-1]

        x = torch.flatten(x, 1)
        x = self.fc(x)

        return x.reshape(-1, self.num_joints, 4)

    def predict(self,
                feats: Tuple[Tensor],
                batch_data_samples: OptSampleList,
                test_cfg: ConfigType = {}) -> Predictions:
        """Predict results from outputs."""

        if test_cfg.get('flip_test', False):
            # TTA: flip test -> feats = [orig, flipped]
            assert isinstance(feats, list) and len(feats) == 2
            flip_indices = batch_data_samples[0].metainfo['flip_indices']
            input_size = batch_data_samples[0].metainfo['input_size']

            _feats, _feats_flip = feats

            _batch_coords = self.forward(_feats)
            _batch_coords[..., 2:] = _batch_coords[..., 2:].sigmoid()

            _batch_coords_flip = flip_coordinates(
                self.forward(_feats_flip),
                flip_indices=flip_indices,
                shift_coords=test_cfg.get('shift_coords', True),
                input_size=input_size)
            _batch_coords_flip[..., 2:] = _batch_coords_flip[..., 2:].sigmoid()

            batch_coords = (_batch_coords + _batch_coords_flip) * 0.5
        else:
            batch_coords = self.forward(feats)  # (B, K, D)
            batch_coords[..., 2:] = batch_coords[..., 2:].sigmoid()

        batch_coords.unsqueeze_(dim=1)  # (B, N, K, D)
        preds = self.decode(batch_coords)

        return preds

    def loss(self,
             inputs: Tuple[Tensor],
             batch_data_samples: OptSampleList,
             train_cfg: ConfigType = {}) -> dict:
        """Calculate losses from a batch of inputs and data samples."""

        pred_outputs = self.forward(inputs)

        keypoint_labels = torch.cat(
            [d.gt_instance_labels.keypoint_labels for d in batch_data_samples])
        keypoint_weights = torch.cat([
            d.gt_instance_labels.keypoint_weights for d in batch_data_samples
        ])

        pred_coords = pred_outputs[:, :, :2]
        pred_sigma = pred_outputs[:, :, 2:4]

        # calculate losses
        losses = dict()
        loss = self.loss_module(pred_coords, pred_sigma, keypoint_labels,
                                keypoint_weights.unsqueeze(-1))

        losses.update(loss_kpt=loss)

        # calculate accuracy
        _, avg_acc, _ = keypoint_pck_accuracy(
            pred=to_numpy(pred_coords),
            gt=to_numpy(keypoint_labels),
            mask=to_numpy(keypoint_weights) > 0,
            thr=0.05,
            norm_factor=np.ones((pred_coords.size(0), 2), dtype=np.float32))

        acc_pose = torch.tensor(avg_acc, device=keypoint_labels.device)
        losses.update(acc_pose=acc_pose)

        return losses

    def _load_state_dict_pre_hook(self, state_dict, prefix, local_meta, *args,
                                  **kwargs):
        """A hook function to convert old-version state dict of
        :class:`TopdownHeatmapSimpleHead` (before MMPose v1.0.0) to a
        compatible format of :class:`HeatmapHead`.

        The hook will be automatically registered during initialization.
        """

        version = local_meta.get('version', None)
        if version and version >= self._version:
            return

        # convert old-version state dict
        keys = list(state_dict.keys())
        for _k in keys:
            v = state_dict.pop(_k)
            k = _k.lstrip(prefix)
            # In old version, "loss" includes the instances of loss,
            # now it should be renamed "loss_module"
            k_parts = k.split('.')
            if k_parts[0] == 'loss':
                # loss.xxx -> loss_module.xxx
                k_new = prefix + 'loss_module.' + '.'.join(k_parts[1:])
            else:
                k_new = _k

            state_dict[k_new] = v

    @property
    def default_init_cfg(self):
        init_cfg = [dict(type='Normal', layer=['Linear'], std=0.01, bias=0)]
        return init_cfg