1 /* Copyright 2016 The TensorFlow Authors. All Rights Reserved.
2
3 Licensed under the Apache License, Version 2.0 (the "License");
4 you may not use this file except in compliance with the License.
5 You may obtain a copy of the License at
6
7 http://www.apache.org/licenses/LICENSE-2.0
8
9 Unless required by applicable law or agreed to in writing, software
10 distributed under the License is distributed on an "AS IS" BASIS,
11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 See the License for the specific language governing permissions and
13 limitations under the License.
14 ==============================================================================*/
15
16 #include "tensorflow/examples/android/jni/object_tracking/tracked_object.h"
17
18 namespace tf_tracking {
19
20 static const float kInitialDistance = 20.0f;
21
InitNormalized(const Image<uint8_t> & src_image,const BoundingBox & position,Image<float> * const dst_image)22 static void InitNormalized(const Image<uint8_t>& src_image,
23 const BoundingBox& position,
24 Image<float>* const dst_image) {
25 BoundingBox scaled_box(position);
26 CopyArea(src_image, scaled_box, dst_image);
27 NormalizeImage(dst_image);
28 }
29
TrackedObject(const std::string & id,const Image<uint8_t> & image,const BoundingBox & bounding_box,ObjectModelBase * const model)30 TrackedObject::TrackedObject(const std::string& id, const Image<uint8_t>& image,
31 const BoundingBox& bounding_box,
32 ObjectModelBase* const model)
33 : id_(id),
34 last_known_position_(bounding_box),
35 last_detection_position_(bounding_box),
36 position_last_computed_time_(-1),
37 object_model_(model),
38 last_detection_thumbnail_(kNormalizedThumbnailSize,
39 kNormalizedThumbnailSize),
40 last_frame_thumbnail_(kNormalizedThumbnailSize, kNormalizedThumbnailSize),
41 tracked_correlation_(0.0f),
42 tracked_match_score_(0.0),
43 num_consecutive_frames_below_threshold_(0),
44 allowable_detection_distance_(Square(kInitialDistance)) {
45 InitNormalized(image, bounding_box, &last_detection_thumbnail_);
46 }
47
~TrackedObject()48 TrackedObject::~TrackedObject() {}
49
UpdatePosition(const BoundingBox & new_position,const int64_t timestamp,const ImageData & image_data,const bool authoratative)50 void TrackedObject::UpdatePosition(const BoundingBox& new_position,
51 const int64_t timestamp,
52 const ImageData& image_data,
53 const bool authoratative) {
54 last_known_position_ = new_position;
55 position_last_computed_time_ = timestamp;
56
57 InitNormalized(*image_data.GetImage(), new_position, &last_frame_thumbnail_);
58
59 const float last_localization_correlation = ComputeCrossCorrelation(
60 last_detection_thumbnail_.data(),
61 last_frame_thumbnail_.data(),
62 last_frame_thumbnail_.data_size_);
63 LOGV("Tracked correlation to last localization: %.6f",
64 last_localization_correlation);
65
66 // Correlation to object model, if it exists.
67 if (object_model_ != NULL) {
68 tracked_correlation_ =
69 object_model_->GetMaxCorrelation(last_frame_thumbnail_);
70 LOGV("Tracked correlation to model: %.6f",
71 tracked_correlation_);
72
73 tracked_match_score_ =
74 object_model_->GetMatchScore(new_position, image_data);
75 LOGV("Tracked match score with model: %.6f",
76 tracked_match_score_.value);
77 } else {
78 // If there's no model to check against, set the tracked correlation to
79 // simply be the correlation to the last set position.
80 tracked_correlation_ = last_localization_correlation;
81 tracked_match_score_ = MatchScore(0.0f);
82 }
83
84 // Determine if it's still being tracked.
85 if (tracked_correlation_ >= kMinimumCorrelationForTracking &&
86 tracked_match_score_ >= kMinimumMatchScore) {
87 num_consecutive_frames_below_threshold_ = 0;
88
89 if (object_model_ != NULL) {
90 object_model_->TrackStep(last_known_position_, *image_data.GetImage(),
91 *image_data.GetIntegralImage(), authoratative);
92 }
93 } else if (tracked_match_score_ < kMatchScoreForImmediateTermination) {
94 if (num_consecutive_frames_below_threshold_ < 1000) {
95 LOGD("Tracked match score is way too low (%.6f), aborting track.",
96 tracked_match_score_.value);
97 }
98
99 // Add an absurd amount of missed frames so that all heuristics will
100 // consider it a lost track.
101 num_consecutive_frames_below_threshold_ += 1000;
102
103 if (object_model_ != NULL) {
104 object_model_->TrackLost();
105 }
106 } else {
107 ++num_consecutive_frames_below_threshold_;
108 allowable_detection_distance_ *= 1.1f;
109 }
110 }
111
OnDetection(ObjectModelBase * const model,const BoundingBox & detection_position,const MatchScore match_score,const int64_t timestamp,const ImageData & image_data)112 void TrackedObject::OnDetection(ObjectModelBase* const model,
113 const BoundingBox& detection_position,
114 const MatchScore match_score,
115 const int64_t timestamp,
116 const ImageData& image_data) {
117 const float overlap = detection_position.PascalScore(last_known_position_);
118 if (overlap > kPositionOverlapThreshold) {
119 // If the position agreement with the current tracked position is good
120 // enough, lock all the current unlocked examples.
121 object_model_->TrackConfirmed();
122 num_consecutive_frames_below_threshold_ = 0;
123 }
124
125 // Before relocalizing, make sure the new proposed position is better than
126 // the existing position by a small amount to prevent thrashing.
127 if (match_score <= tracked_match_score_ + kMatchScoreBuffer) {
128 LOGI("Not relocalizing since new match is worse: %.6f < %.6f + %.6f",
129 match_score.value, tracked_match_score_.value,
130 kMatchScoreBuffer.value);
131 return;
132 }
133
134 LOGI("Relocalizing! From (%.1f, %.1f)[%.1fx%.1f] to "
135 "(%.1f, %.1f)[%.1fx%.1f]: %.6f > %.6f",
136 last_known_position_.left_, last_known_position_.top_,
137 last_known_position_.GetWidth(), last_known_position_.GetHeight(),
138 detection_position.left_, detection_position.top_,
139 detection_position.GetWidth(), detection_position.GetHeight(),
140 match_score.value, tracked_match_score_.value);
141
142 if (overlap < kPositionOverlapThreshold) {
143 // The path might be good, it might be bad, but it's no longer a path
144 // since we're moving the box to a new position, so just nuke it from
145 // orbit to be safe.
146 object_model_->TrackLost();
147 }
148
149 object_model_ = model;
150
151 // Reset the last detected appearance.
152 InitNormalized(
153 *image_data.GetImage(), detection_position, &last_detection_thumbnail_);
154
155 num_consecutive_frames_below_threshold_ = 0;
156 last_detection_position_ = detection_position;
157
158 UpdatePosition(detection_position, timestamp, image_data, false);
159 allowable_detection_distance_ = Square(kInitialDistance);
160 }
161
162 } // namespace tf_tracking
163