File size: 10,504 Bytes
47af768
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204

import os
import numpy as np
from scipy.optimize import linear_sum_assignment
from ._base_metric import _BaseMetric
from .. import _timing


class HOTA(_BaseMetric):
    """Class which implements the HOTA metrics.
    See: https://link.springer.com/article/10.1007/s11263-020-01375-2
    """

    def __init__(self, config=None):
        super().__init__()
        self.plottable = True
        self.array_labels = np.arange(0.05, 0.99, 0.05)
        self.integer_array_fields = ['HOTA_TP', 'HOTA_FN', 'HOTA_FP']
        self.float_array_fields = ['HOTA', 'DetA', 'AssA', 'DetRe', 'DetPr', 'AssRe', 'AssPr', 'LocA', 'OWTA']
        self.float_fields = ['HOTA(0)', 'LocA(0)', 'HOTALocA(0)']
        self.fields = self.float_array_fields + self.integer_array_fields + self.float_fields
        self.summary_fields = self.float_array_fields + self.float_fields

    @_timing.time
    def eval_sequence(self, data):
        """Calculates the HOTA metrics for one sequence"""

        # Initialise results
        res = {}
        for field in self.float_array_fields + self.integer_array_fields:
            res[field] = np.zeros((len(self.array_labels)), dtype=np.float)
        for field in self.float_fields:
            res[field] = 0

        # Return result quickly if tracker or gt sequence is empty
        if data['num_tracker_dets'] == 0:
            res['HOTA_FN'] = data['num_gt_dets'] * np.ones((len(self.array_labels)), dtype=np.float)
            res['LocA'] = np.ones((len(self.array_labels)), dtype=np.float)
            res['LocA(0)'] = 1.0
            return res
        if data['num_gt_dets'] == 0:
            res['HOTA_FP'] = data['num_tracker_dets'] * np.ones((len(self.array_labels)), dtype=np.float)
            res['LocA'] = np.ones((len(self.array_labels)), dtype=np.float)
            res['LocA(0)'] = 1.0
            return res

        # Variables counting global association
        potential_matches_count = np.zeros((data['num_gt_ids'], data['num_tracker_ids']))
        gt_id_count = np.zeros((data['num_gt_ids'], 1))
        tracker_id_count = np.zeros((1, data['num_tracker_ids']))

        # First loop through each timestep and accumulate global track information.
        for t, (gt_ids_t, tracker_ids_t) in enumerate(zip(data['gt_ids'], data['tracker_ids'])):
            # Count the potential matches between ids in each timestep
            # These are normalised, weighted by the match similarity.
            similarity = data['similarity_scores'][t]
            sim_iou_denom = similarity.sum(0)[np.newaxis, :] + similarity.sum(1)[:, np.newaxis] - similarity
            sim_iou = np.zeros_like(similarity)
            sim_iou_mask = sim_iou_denom > 0 + np.finfo('float').eps
            sim_iou[sim_iou_mask] = similarity[sim_iou_mask] / sim_iou_denom[sim_iou_mask]
            potential_matches_count[gt_ids_t[:, np.newaxis], tracker_ids_t[np.newaxis, :]] += sim_iou

            # Calculate the total number of dets for each gt_id and tracker_id.
            gt_id_count[gt_ids_t] += 1
            tracker_id_count[0, tracker_ids_t] += 1

        # Calculate overall jaccard alignment score (before unique matching) between IDs
        global_alignment_score = potential_matches_count / (gt_id_count + tracker_id_count - potential_matches_count)
        matches_counts = [np.zeros_like(potential_matches_count) for _ in self.array_labels]

        # Calculate scores for each timestep
        for t, (gt_ids_t, tracker_ids_t) in enumerate(zip(data['gt_ids'], data['tracker_ids'])):
            # Deal with the case that there are no gt_det/tracker_det in a timestep.
            if len(gt_ids_t) == 0:
                for a, alpha in enumerate(self.array_labels):
                    res['HOTA_FP'][a] += len(tracker_ids_t)
                continue
            if len(tracker_ids_t) == 0:
                for a, alpha in enumerate(self.array_labels):
                    res['HOTA_FN'][a] += len(gt_ids_t)
                continue

            # Get matching scores between pairs of dets for optimizing HOTA
            similarity = data['similarity_scores'][t]
            score_mat = global_alignment_score[gt_ids_t[:, np.newaxis], tracker_ids_t[np.newaxis, :]] * similarity

            # Hungarian algorithm to find best matches
            match_rows, match_cols = linear_sum_assignment(-score_mat)

            # Calculate and accumulate basic statistics
            for a, alpha in enumerate(self.array_labels):
                actually_matched_mask = similarity[match_rows, match_cols] >= alpha - np.finfo('float').eps
                alpha_match_rows = match_rows[actually_matched_mask]
                alpha_match_cols = match_cols[actually_matched_mask]
                num_matches = len(alpha_match_rows)
                res['HOTA_TP'][a] += num_matches
                res['HOTA_FN'][a] += len(gt_ids_t) - num_matches
                res['HOTA_FP'][a] += len(tracker_ids_t) - num_matches
                if num_matches > 0:
                    res['LocA'][a] += sum(similarity[alpha_match_rows, alpha_match_cols])
                    matches_counts[a][gt_ids_t[alpha_match_rows], tracker_ids_t[alpha_match_cols]] += 1

        # Calculate association scores (AssA, AssRe, AssPr) for the alpha value.
        # First calculate scores per gt_id/tracker_id combo and then average over the number of detections.
        for a, alpha in enumerate(self.array_labels):
            matches_count = matches_counts[a]
            ass_a = matches_count / np.maximum(1, gt_id_count + tracker_id_count - matches_count)
            res['AssA'][a] = np.sum(matches_count * ass_a) / np.maximum(1, res['HOTA_TP'][a])
            ass_re = matches_count / np.maximum(1, gt_id_count)
            res['AssRe'][a] = np.sum(matches_count * ass_re) / np.maximum(1, res['HOTA_TP'][a])
            ass_pr = matches_count / np.maximum(1, tracker_id_count)
            res['AssPr'][a] = np.sum(matches_count * ass_pr) / np.maximum(1, res['HOTA_TP'][a])

        # Calculate final scores
        res['LocA'] = np.maximum(1e-10, res['LocA']) / np.maximum(1e-10, res['HOTA_TP'])
        res = self._compute_final_fields(res)
        return res

    def combine_sequences(self, all_res):
        """Combines metrics across all sequences"""
        res = {}
        for field in self.integer_array_fields:
            res[field] = self._combine_sum(all_res, field)
        for field in ['AssRe', 'AssPr', 'AssA']:
            res[field] = self._combine_weighted_av(all_res, field, res, weight_field='HOTA_TP')
        loca_weighted_sum = sum([all_res[k]['LocA'] * all_res[k]['HOTA_TP'] for k in all_res.keys()])
        res['LocA'] = np.maximum(1e-10, loca_weighted_sum) / np.maximum(1e-10, res['HOTA_TP'])
        res = self._compute_final_fields(res)
        return res

    def combine_classes_class_averaged(self, all_res, ignore_empty_classes=False):
        """Combines metrics across all classes by averaging over the class values.
        If 'ignore_empty_classes' is True, then it only sums over classes with at least one gt or predicted detection.
        """
        res = {}
        for field in self.integer_array_fields:
            if ignore_empty_classes:
                res[field] = self._combine_sum(
                    {k: v for k, v in all_res.items()
                     if (v['HOTA_TP'] + v['HOTA_FN'] + v['HOTA_FP'] > 0 + np.finfo('float').eps).any()}, field)
            else:
                res[field] = self._combine_sum({k: v for k, v in all_res.items()}, field)

        for field in self.float_fields + self.float_array_fields:
            if ignore_empty_classes:
                res[field] = np.mean([v[field] for v in all_res.values() if
                                      (v['HOTA_TP'] + v['HOTA_FN'] + v['HOTA_FP'] > 0 + np.finfo('float').eps).any()],
                                     axis=0)
            else:
                res[field] = np.mean([v[field] for v in all_res.values()], axis=0)
        return res

    def combine_classes_det_averaged(self, all_res):
        """Combines metrics across all classes by averaging over the detection values"""
        res = {}
        for field in self.integer_array_fields:
            res[field] = self._combine_sum(all_res, field)
        for field in ['AssRe', 'AssPr', 'AssA']:
            res[field] = self._combine_weighted_av(all_res, field, res, weight_field='HOTA_TP')
        loca_weighted_sum = sum([all_res[k]['LocA'] * all_res[k]['HOTA_TP'] for k in all_res.keys()])
        res['LocA'] = np.maximum(1e-10, loca_weighted_sum) / np.maximum(1e-10, res['HOTA_TP'])
        res = self._compute_final_fields(res)
        return res

    @staticmethod
    def _compute_final_fields(res):
        """Calculate sub-metric ('field') values which only depend on other sub-metric values.
        This function is used both for both per-sequence calculation, and in combining values across sequences.
        """
        res['DetRe'] = res['HOTA_TP'] / np.maximum(1, res['HOTA_TP'] + res['HOTA_FN'])
        res['DetPr'] = res['HOTA_TP'] / np.maximum(1, res['HOTA_TP'] + res['HOTA_FP'])
        res['DetA'] = res['HOTA_TP'] / np.maximum(1, res['HOTA_TP'] + res['HOTA_FN'] + res['HOTA_FP'])
        res['HOTA'] = np.sqrt(res['DetA'] * res['AssA'])
        res['OWTA'] = np.sqrt(res['DetRe'] * res['AssA'])

        res['HOTA(0)'] = res['HOTA'][0]
        res['LocA(0)'] = res['LocA'][0]
        res['HOTALocA(0)'] = res['HOTA(0)']*res['LocA(0)']
        return res

    def plot_single_tracker_results(self, table_res, tracker, cls, output_folder):
        """Create plot of results"""

        # Only loaded when run to reduce minimum requirements
        from matplotlib import pyplot as plt

        res = table_res['COMBINED_SEQ']
        styles_to_plot = ['r', 'b', 'g', 'b--', 'b:', 'g--', 'g:', 'm']
        for name, style in zip(self.float_array_fields, styles_to_plot):
            plt.plot(self.array_labels, res[name], style)
        plt.xlabel('alpha')
        plt.ylabel('score')
        plt.title(tracker + ' - ' + cls)
        plt.axis([0, 1, 0, 1])
        legend = []
        for name in self.float_array_fields:
            legend += [name + ' (' + str(np.round(np.mean(res[name]), 2)) + ')']
        plt.legend(legend, loc='lower left')
        out_file = os.path.join(output_folder, cls + '_plot.pdf')
        os.makedirs(os.path.dirname(out_file), exist_ok=True)
        plt.savefig(out_file)
        plt.savefig(out_file.replace('.pdf', '.png'))
        plt.clf()