Move initial track selection (via _resetTracks) inside TrackSelection.

Also fixes:
 - SIFT only freely available in OpenCV 4.4.0+.
 - Correct return type in videoImage.jpgread.

Author: philip-lamb

Source/ARX/ARVideo/Image/videoImage.c

@@ -133,7 +133,7 @@ static int jpegRead(FILE *fp, unsigned char *buf, int bufWidth, int bufHeight, A
         cinfo.image_height < 0 || cinfo.image_height > 32767) {
         ARLOGe("JPEG image size too large.");
         jpeg_destroy_decompress(&cinfo);
-        return NULL;
+        return (FALSE);
     }
 
     if (pixFormat != bufPixFormat) { // Pixel format conversion required?

Source/ARX/OCVT/OCVConfig.cpp

@@ -38,7 +38,6 @@
 
 int minRequiredDetectedFeatures = 50; ///< Minimum number of detected features required to consider a target matched.
 const int markerTemplateWidth = 15; ///< Width in pixels of image patches used in template matching.
-const int k_OCVTOpticalFlowMaxPyrLevel = 3; ///< Maximum number of levels in optical flow image pyramid (0 = base level only).
 const cv::Size subPixWinSize(10,10);
 const cv::Size winSize(31,31); ///< Window size to use in optical flow search.
 cv::TermCriteria termcrit(cv::TermCriteria::COUNT|cv::TermCriteria::EPS,20,0.03);

Source/ARX/OCVT/OCVConfig.h

@@ -61,9 +61,13 @@
 #include <opencv2/calib3d.hpp>
 #include <ARX/OCVT/PlanarTracker.h>
 
+/** @file */
+
+/// @def k_OCVTOpticalFlowMaxPyrLevel Maximum number of levels in optical flow image pyramid (0 = base level only).
+#define k_OCVTOpticalFlowMaxPyrLevel 3
+
 OCV_EXTERN extern int minRequiredDetectedFeatures; ///< Minimum number of detected features required to consider a target matched.
 OCV_EXTERN extern const int markerTemplateWidth; ///< Width in pixels of image patches used in template matching.
-OCV_EXTERN extern const int k_OCVTOpticalFlowMaxPyrLevel; ///< Maximum number of levels in optical flow image pyramid (0 = base level only).
 OCV_EXTERN extern const cv::Size subPixWinSize;
 OCV_EXTERN extern const cv::Size winSize; ///< Window size to use in optical flow search.
 OCV_EXTERN extern cv::TermCriteria termcrit;

Source/ARX/OCVT/OCVFeatureDetector.cpp

@@ -89,7 +89,12 @@ void OCVFeatureDetector::CreateORBFeatureDetector()
 
 void OCVFeatureDetector::CreateSIFTFeatureDetector()
 {
+#if CV_VERSION_MAJOR > 4 || (CV_VERSION_MAJOR == 4 && CV_VERSION_MINOR >= 4)
     _featureDetector = cv::SIFT::create();
+#else
+    // For versions without SIFT, BRISK is best alternative.
+    _featureDetector = cv::BRISK::create();
+#endif
     _matcher = cv::BFMatcher::create();
 }
 

Source/ARX/OCVT/PlanarTracker.cpp

@@ -209,8 +209,8 @@ class PlanarTracker::PlanarTrackerImpl
                 //std::cout << "New marker detected" << std::endl;
                 _trackables[bestMatchIndex]._isDetected = true;
                 // Since we've just detected the marker, make sure next invocation of
-                // SelectTrackablePoints() for this marker resets the selection.
-                _trackables[bestMatchIndex]._resetTracks = true;
+                // GetInitialFeatures() for this marker makes a new selection.
+                _trackables[bestMatchIndex]._trackSelection.ResetSelection();
                 _trackables[bestMatchIndex]._trackSelection.SetHomography(homoInfo.homography);
 
                 // Use the homography to form the initial estimate of the bounding box.
@@ -227,17 +227,6 @@ class PlanarTracker::PlanarTrackerImpl
         }
     }
 
-    std::vector<cv::Point2f> SelectTrackablePoints(int trackableIndex)
-    {
-        if (_trackables[trackableIndex]._resetTracks) {
-            _trackables[trackableIndex]._trackSelection.SelectPoints();
-            _trackables[trackableIndex]._resetTracks = false;
-            return _trackables[trackableIndex]._trackSelection.GetSelectedFeatures();
-        } else {
-            return _trackables[trackableIndex]._trackSelection.GetTrackedFeatures();
-        }
-    }
-    
     bool RunOpticalFlow(int trackableId, const std::vector<cv::Point2f>& trackablePoints, const std::vector<cv::Point2f>& trackablePointsWarped)
     {
         std::vector<cv::Point2f> flowResultPoints, trackablePointsWarpedResult;
@@ -292,7 +281,7 @@ class PlanarTracker::PlanarTrackerImpl
                     }
                 }
                 if (_frameCount > 1) {
-                    _trackables[trackableId]._resetTracks = true;
+                    _trackables[trackableId]._trackSelection.ResetSelection();
                 }
                 return true;
             }
@@ -537,7 +526,7 @@ class PlanarTracker::PlanarTrackerImpl
                     //float templateScaleFactor = (float)(1 << templatePyrLevel);
                     //std::cout << "templatePyrLevel=" << templatePyrLevel << ", templateScaleFactor=" << templateScaleFactor << "." << std::endl;
 
-                    std::vector<cv::Point2f> trackablePoints = SelectTrackablePoints(i);
+                    std::vector<cv::Point2f> trackablePoints = _trackables[i]._trackSelection.GetInitialFeatures();
                     std::vector<cv::Point2f> trackablePointsWarped = _trackables[i]._trackSelection.GetTrackedFeaturesWarped();
 
                     if (_frameCount > 0 && _prevPyramid.size() > 0) {
@@ -648,7 +637,6 @@ class PlanarTracker::PlanarTrackerImpl
                     newTrackable._bBox.push_back(cv::Point2f(0, newTrackable._height));
                     newTrackable._isTracking = false;
                     newTrackable._isDetected = false;
-                    newTrackable._resetTracks = false;
                     newTrackable._trackSelection = TrackingPointSelector(newTrackable._cornerPoints, newTrackable._width, newTrackable._height, markerTemplateWidth);
                     _trackables.push_back(newTrackable);
                 }
@@ -686,7 +674,6 @@ class PlanarTracker::PlanarTrackerImpl
             newTrackable._bBox.push_back(cv::Point2f(0, newTrackable._height));
             newTrackable._isTracking = false;
             newTrackable._isDetected = false;
-            newTrackable._resetTracks = false;
             newTrackable._trackSelection = TrackingPointSelector(newTrackable._cornerPoints, newTrackable._width, newTrackable._height, markerTemplateWidth);
 
             _trackables.push_back(newTrackable);

Source/ARX/OCVT/TrackableInfo.h

@@ -60,8 +60,6 @@ class TrackableInfo
     /// The four points defining the bound-box of a detected trackable in the video frame.
     std::vector<cv::Point2f> _bBoxTransformed;
     bool _isTracking, _isDetected;
-    /// If set to true, TrackSelection.SelectPoints will be invoked in SelectTrackablePoints, selecting new points and resetting their tracking status.
-    bool _resetTracks;
 
     std::vector<cv::Point2f> _cornerPoints;
     TrackingPointSelector _trackSelection;

Source/ARX/OCVT/TrackingPointSelector.cpp

@@ -40,12 +40,12 @@
 
 TrackingPointSelector::TrackingPointSelector()
 {
-    
 }
 
-TrackingPointSelector::TrackingPointSelector(std::vector<cv::Point2f> pts, int width, int height, int markerTemplateWidth)
+TrackingPointSelector::TrackingPointSelector(std::vector<cv::Point2f> pts, int width, int height, int markerTemplateWidth) :
+    _reset(false),
+    _pts(pts)
 {
-    _pts = pts;
     DistributeBins(width, height, markerTemplateWidth);
 }
 
@@ -107,12 +107,16 @@ void TrackingPointSelector::UpdatePointStatus(std::vector<uchar> status)
     }
 }
 
-/**
- @brief Selects a random template from each bin for tracking.
-    Should be called when either a marker has just been detected.
- */
-void TrackingPointSelector::SelectPoints()
+void TrackingPointSelector::ResetSelection()
+{
+    _reset = true;
+}
+
+std::vector<cv::Point2f> TrackingPointSelector::GetInitialFeatures()
 {
+    if (!_reset) return GetTrackedFeatures();
+    _reset = false;
+    
     // Reset state of all points to not selected and not tracking.
     _selectedPts.clear();
     for (auto &bin : trackingPointBin) {
@@ -122,6 +126,8 @@ void TrackingPointSelector::SelectPoints()
         }
     }
 
+    // Selects a random template from each bin for tracking.
+    std::vector<cv::Point2f> ret;
     for (auto &bin : trackingPointBin) {
         size_t pointCount = bin.second.size();
         if (pointCount > 0) { // If there are points in the bin.
@@ -130,19 +136,11 @@ void TrackingPointSelector::SelectPoints()
             bin.second[tIndex].SetSelected(true);
             bin.second[tIndex].SetTracking(true);
             _selectedPts.push_back(bin.second[tIndex]);
+            
+            ret.push_back(bin.second[tIndex].pt);
         }
     }
-}
-    
-std::vector<cv::Point2f> TrackingPointSelector::GetSelectedFeatures()
-{
-    std::vector<cv::Point2f> selectedPoints;
-    for (std::vector<TrackedPoint>::iterator it = _selectedPts.begin(); it != _selectedPts.end(); ++it) {
-        if (it->IsSelected()) {
-            selectedPoints.push_back(it->pt);
-        }
-    }
-    return selectedPoints;
+    return ret;
 }
 
 std::vector<cv::Point2f> TrackingPointSelector::GetTrackedFeatures()

Source/ARX/OCVT/TrackingPointSelector.h

@@ -61,10 +61,16 @@ class TrackingPointSelector
 
     void UpdatePointStatus(std::vector<uchar> status);
 
-    /// Reset selected points and then randomly select one point from each bin.
-    void SelectPoints();
+    /**
+     @brief Signal that the next call to GetInitialFeatures should return a new selection.
+     */
+    void ResetSelection();
 
-    std::vector<cv::Point2f> GetSelectedFeatures();
+    /**
+     @brief If reset, then selects an initial random template from each bin for tracking,
+        and returns this set. If not reset then returns the same set as GetTrackedFeatures.
+     */
+    std::vector<cv::Point2f> GetInitialFeatures();
 
     std::vector<cv::Point2f> GetTrackedFeatures();
 
@@ -78,10 +84,10 @@ class TrackingPointSelector
     OCV_EXTERN void CleanUp();
 
 private:
-    std::vector<TrackedPoint> _selectedPts;
+    bool _reset;
     std::vector<cv::Point2f> _pts;
     std::map<int, std::vector<TrackedPoint> > trackingPointBin;
     cv::Mat _homography;
-
+    std::vector<TrackedPoint> _selectedPts;
 };
 #endif //TRACKINGPOINTSELECTOR