File size: 4,940 Bytes
a249588
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# Copyright (c) OpenMMLab. All rights reserved.
from typing import Optional, Sequence, Tuple, Union

import torch
from torch import Tensor, nn

from mmpose.evaluation.functional import keypoint_mpjpe
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 TrajectoryRegressionHead(BaseHead):
    """Trajectory Regression head of `VideoPose3D`_ by Dario et al (CVPR'2019).

    Args:
        in_channels (int | sequence[int]): Number of input channels
        num_joints (int): Number of joints
        loss (Config): Config for trajectory loss. Defaults to use
            :class:`MPJPELoss`
        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

    .. _`VideoPose3D`: https://arxiv.org/abs/1811.11742
    """

    _version = 2

    def __init__(self,
                 in_channels: Union[int, Sequence[int]],
                 num_joints: int,
                 loss: ConfigType = dict(
                     type='MPJPELoss', 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.conv = nn.Conv1d(in_channels, self.num_joints * 3, 1)

    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 = self.conv(x)

        return x.reshape(-1, self.num_joints, 3)

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

        Returns:
            preds (sequence[InstanceData]): Prediction results.
                Each contains the following fields:

                - keypoints: Predicted keypoints of shape (B, N, K, D).
                - keypoint_scores: Scores of predicted keypoints of shape
                  (B, N, K).
        """

        batch_coords = self.forward(feats)  # (B, K, D)

        # Restore global position with target_root
        target_root = batch_data_samples[0].metainfo.get('target_root', None)
        if target_root is not None:
            target_root = torch.stack([
                torch.from_numpy(b.metainfo['target_root'])
                for b in batch_data_samples
            ])
        else:
            target_root = torch.stack([
                torch.empty((0), dtype=torch.float32)
                for _ in batch_data_samples
            ])

        preds = self.decode((batch_coords, target_root))

        return preds

    def loss(self,
             inputs: Union[Tensor, 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)

        lifting_target_label = torch.cat([
            d.gt_instance_labels.lifting_target_label
            for d in batch_data_samples
        ])
        trajectory_weights = torch.cat([
            d.gt_instance_labels.trajectory_weights for d in batch_data_samples
        ])

        # calculate losses
        losses = dict()
        loss = self.loss_module(pred_outputs, lifting_target_label,
                                trajectory_weights.unsqueeze(-1))

        losses.update(loss_traj=loss)

        # calculate accuracy
        mpjpe_err = keypoint_mpjpe(
            pred=to_numpy(pred_outputs),
            gt=to_numpy(lifting_target_label),
            mask=to_numpy(trajectory_weights) > 0)

        mpjpe_traj = torch.tensor(
            mpjpe_err, device=lifting_target_label.device)
        losses.update(mpjpe_traj=mpjpe_traj)

        return losses

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