/ocr/ocrservice/jni/opticalflow/feature_detector.h

 1// Copyright 2010 Google Inc. All Rights Reserved.
 2// Author: andrewharp@google.com (Andrew Harp)
 3
 4#ifndef JAVA_COM_GOOGLE_ANDROID_APPS_UNVEIL_JNI_OPTICALFLOW_FEATURE_DETECTOR_H_
 5#define JAVA_COM_GOOGLE_ANDROID_APPS_UNVEIL_JNI_OPTICALFLOW_FEATURE_DETECTOR_H_
 6
 7namespace flow {
 8
 9// Add features along a regular grid.
10int32 seedFeatures(const Image<uint8>& frame,
11                   const int32 num_x, const int32 num_y,
12                   const float32 left, const float32 top,
13                   const float32 right, const float32 bottom,
14                   const int32 type, Point2D* const features);
15
16// Compute the corneriness of a point in the image.
17float32 harrisFilter(const Image<int32>& I_x, const Image<int32>& I_y,
18                     const int32 x, const int32 y);
19
20// Scan the frame for potential features using the FAST feature detector.
21int32 findFastFeatures(const Image<uint8>& frame,
22                       const int32 max_num_features,
23                       Point2D* const features,
24                       Image<uint8>* const best_feature_map);
25
26// Score a bunch of candidate features.  Assigns the scores to the input
27// candidate_features array entries.
28void scoreFeatures(const Image<int32>& I_x, const Image<int32>& I_y,
29                   const int32 num_candidates,
30                   Point2D* const candidate_features);
31
32// Copy the best features (with local non-max suppression) from
33// candidate_features to final_features.
34// Returns the number of features copied.
35int32 sortAndSelect(const int32 num_candidates,
36                    const int32 max_features,
37                    const Image<bool>& interest_map,
38                    Point2D* const candidate_features,
39                    Point2D* const final_features,
40                    Image<uint8>* const best_feature_map);
41
42}  // namespace flow
43
44#endif  // JAVA_COM_GOOGLE_ANDROID_APPS_UNVEIL_JNI_OPTICALFLOW_FEATURE_DETECTOR_H_