File size: 6,288 Bytes
2de1f98
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# Copyright (c) OpenMMLab. All rights reserved.
import numpy as np

from .mesh_eval import compute_similarity_transform


def keypoint_mpjpe(pred, gt, mask, alignment='none'):
    """Calculate the mean per-joint position error (MPJPE) and the error after
    rigid alignment with the ground truth (P-MPJPE).

    Note:
        - batch_size: N
        - num_keypoints: K
        - keypoint_dims: C

    Args:
        pred (np.ndarray): Predicted keypoint location with shape [N, K, C].
        gt (np.ndarray): Groundtruth keypoint location with shape [N, K, C].
        mask (np.ndarray): Visibility of the target with shape [N, K].
            False for invisible joints, and True for visible.
            Invisible joints will be ignored for accuracy calculation.
        alignment (str, optional): method to align the prediction with the
            groundtruth. Supported options are:

                - ``'none'``: no alignment will be applied
                - ``'scale'``: align in the least-square sense in scale
                - ``'procrustes'``: align in the least-square sense in
                    scale, rotation and translation.
    Returns:
        tuple: A tuple containing joint position errors

        - (float | np.ndarray): mean per-joint position error (mpjpe).
        - (float | np.ndarray): mpjpe after rigid alignment with the
            ground truth (p-mpjpe).
    """
    assert mask.any()

    if alignment == 'none':
        pass
    elif alignment == 'procrustes':
        pred = np.stack([
            compute_similarity_transform(pred_i, gt_i)
            for pred_i, gt_i in zip(pred, gt)
        ])
    elif alignment == 'scale':
        pred_dot_pred = np.einsum('nkc,nkc->n', pred, pred)
        pred_dot_gt = np.einsum('nkc,nkc->n', pred, gt)
        scale_factor = pred_dot_gt / pred_dot_pred
        pred = pred * scale_factor[:, None, None]
    else:
        raise ValueError(f'Invalid value for alignment: {alignment}')

    error = np.linalg.norm(pred - gt, ord=2, axis=-1)[mask].mean()

    return error


def keypoint_3d_pck(pred, gt, mask, alignment='none', threshold=0.15):
    """Calculate the Percentage of Correct Keypoints (3DPCK) w. or w/o rigid
    alignment.

    Paper ref: `Monocular 3D Human Pose Estimation In The Wild Using Improved
    CNN Supervision' 3DV'2017. <https://arxiv.org/pdf/1611.09813>`__ .

    Note:
        - batch_size: N
        - num_keypoints: K
        - keypoint_dims: C

    Args:
        pred (np.ndarray[N, K, C]): Predicted keypoint location.
        gt (np.ndarray[N, K, C]): Groundtruth keypoint location.
        mask (np.ndarray[N, K]): Visibility of the target. False for invisible
            joints, and True for visible. Invisible joints will be ignored for
            accuracy calculation.
        alignment (str, optional): method to align the prediction with the
            groundtruth. Supported options are:

            - ``'none'``: no alignment will be applied
            - ``'scale'``: align in the least-square sense in scale
            - ``'procrustes'``: align in the least-square sense in scale,
                rotation and translation.

        threshold:  If L2 distance between the prediction and the groundtruth
            is less then threshold, the predicted result is considered as
            correct. Default: 0.15 (m).

    Returns:
        pck: percentage of correct keypoints.
    """
    assert mask.any()

    if alignment == 'none':
        pass
    elif alignment == 'procrustes':
        pred = np.stack([
            compute_similarity_transform(pred_i, gt_i)
            for pred_i, gt_i in zip(pred, gt)
        ])
    elif alignment == 'scale':
        pred_dot_pred = np.einsum('nkc,nkc->n', pred, pred)
        pred_dot_gt = np.einsum('nkc,nkc->n', pred, gt)
        scale_factor = pred_dot_gt / pred_dot_pred
        pred = pred * scale_factor[:, None, None]
    else:
        raise ValueError(f'Invalid value for alignment: {alignment}')

    error = np.linalg.norm(pred - gt, ord=2, axis=-1)
    pck = (error < threshold).astype(np.float32)[mask].mean() * 100

    return pck


def keypoint_3d_auc(pred, gt, mask, alignment='none'):
    """Calculate the Area Under the Curve (3DAUC) computed for a range of 3DPCK
    thresholds.

    Paper ref: `Monocular 3D Human Pose Estimation In The Wild Using Improved
    CNN Supervision' 3DV'2017. <https://arxiv.org/pdf/1611.09813>`__ .
    This implementation is derived from mpii_compute_3d_pck.m, which is
    provided as part of the MPI-INF-3DHP test data release.

    Note:
        batch_size: N
        num_keypoints: K
        keypoint_dims: C

    Args:
        pred (np.ndarray[N, K, C]): Predicted keypoint location.
        gt (np.ndarray[N, K, C]): Groundtruth keypoint location.
        mask (np.ndarray[N, K]): Visibility of the target. False for invisible
            joints, and True for visible. Invisible joints will be ignored for
            accuracy calculation.
        alignment (str, optional): method to align the prediction with the
            groundtruth. Supported options are:

            - ``'none'``: no alignment will be applied
            - ``'scale'``: align in the least-square sense in scale
            - ``'procrustes'``: align in the least-square sense in scale,
                rotation and translation.

    Returns:
        auc: AUC computed for a range of 3DPCK thresholds.
    """
    assert mask.any()

    if alignment == 'none':
        pass
    elif alignment == 'procrustes':
        pred = np.stack([
            compute_similarity_transform(pred_i, gt_i)
            for pred_i, gt_i in zip(pred, gt)
        ])
    elif alignment == 'scale':
        pred_dot_pred = np.einsum('nkc,nkc->n', pred, pred)
        pred_dot_gt = np.einsum('nkc,nkc->n', pred, gt)
        scale_factor = pred_dot_gt / pred_dot_pred
        pred = pred * scale_factor[:, None, None]
    else:
        raise ValueError(f'Invalid value for alignment: {alignment}')

    error = np.linalg.norm(pred - gt, ord=2, axis=-1)

    thresholds = np.linspace(0., 0.15, 31)
    pck_values = np.zeros(len(thresholds))
    for i in range(len(thresholds)):
        pck_values[i] = (error < thresholds[i]).astype(np.float32)[mask].mean()

    auc = pck_values.mean() * 100

    return auc