public override bool Track(List <AbstractTrackPoint> _previousPoints, Bitmap _CurrentImage, long _t, out AbstractTrackPoint _currentPoint)
{
//---------------------------------------------------------------------
// The input informations we have at hand are:
// - The current bitmap we have to find the point into.
// - The coordinates of all the previous points tracked.
// - Previous tracking infos, stored in the TrackPoints tracked so far.
//---------------------------------------------------------------------
bool bMatched = false;
TrackPointSURF lastTrackPoint = (TrackPointSURF)_previousPoints[_previousPoints.Count - 1];
// Create a point centered on last match.
// This will find and register all the SURF features located in the search zone.
// Test with grayscale image.
Bitmap grayCurrentImage = Grayscale.CommonAlgorithms.BT709.Apply(_CurrentImage);
_currentPoint = CreateTrackPoint(false, lastTrackPoint.X, lastTrackPoint.Y, 1.0f, _t, grayCurrentImage, _previousPoints);
if (_currentPoint == null)
{
// Untrackable area.
}
else
{
if (((TrackPointSURF)_currentPoint).FoundFeatures.Count > 0)
{
// Feature matching.
// Look for the nearest neighbour to the previous match, in the list of newly found features.
Match m = null;
COpenSURF.MatchPoint(lastTrackPoint.MatchedFeature, ((TrackPointSURF)_currentPoint).FoundFeatures, out m);
// Also look for a match of the first feature, to compensate for occlusion and drift).
Match m2 = null;
TrackPointSURF firstTrackPoint = (TrackPointSURF)_previousPoints[0];
COpenSURF.MatchPoint(firstTrackPoint.MatchedFeature, ((TrackPointSURF)_currentPoint).FoundFeatures, out m2);
// Take the best match out of the two.
Match matchedFeature = (m.Distance2 < m2.Distance2) ? m : m2;
// TODO:
// check if distance (match similarity) is over a given threshold.
// 3. Store the new matched feature with associated data.
((TrackPointSURF)_currentPoint).MatchedFeature = matchedFeature.Ipt2;
_currentPoint.X = ((TrackPointSURF)_currentPoint).SearchWindow.X + (int)matchedFeature.Ipt2.x;
_currentPoint.Y = ((TrackPointSURF)_currentPoint).SearchWindow.Y + (int)matchedFeature.Ipt2.y;
log.Debug(String.Format("Tracking result: [{0};{1}]", _currentPoint.X, _currentPoint.Y));
bMatched = true;
}
if (m_bMonitoring)
{
log.Debug(_currentPoint.ToString());
}
// Problems:
// The user did not choose a feature, so we have extra work to do to keep the correspondance between
// the feature saved in the track point and the actual coordinates the user is looking for.
// Currently we just discard the user's point entirely and try to track the closest feature.
}
return(bMatched);
}
public override AbstractTrackPoint CreateTrackPoint(bool _manual, int _x, int _y, double _fSimilarity, long _t, Bitmap _CurrentImage, List <AbstractTrackPoint> _previousPoints)
{
// Creates a TrackPoint from the input image at the given coordinates.
// Find features in the search window.
// Scale-space image of the search window.
int searchLeft = _x - (m_SearchWindowSize.Width / 2);
int searchTop = _y - (m_SearchWindowSize.Height / 2);
Rectangle searchZone = new Rectangle(searchLeft, searchTop, m_SearchWindowSize.Width, m_SearchWindowSize.Height);
Bitmap searchImage = new Bitmap(m_SearchWindowSize.Width, m_SearchWindowSize.Height, PixelFormat.Format24bppRgb);
Graphics g = Graphics.FromImage(searchImage);
Rectangle rDst = new Rectangle(0, 0, m_SearchWindowSize.Width, m_SearchWindowSize.Height);
g.DrawImage(_CurrentImage, rDst, searchZone, GraphicsUnit.Pixel);
//g.Dispose();
IplImage pIplImage = IplImage.LoadImage(searchImage);
pIplImage = pIplImage.BuildIntegral(null);
List <Ipoint> ipts = new List <Ipoint>();
CFastHessian pCFastHessian = new CFastHessian(pIplImage, ref ipts, m_iOctaves, m_iIntervals, m_iInitSample, m_fThreshold, m_iInterpolationSteps);
// Fill the scale-space image with actual data and finds the local extrema.
pCFastHessian.getIpoints();
// Fill the descriptor field, orientation and laplacian of the feature.
Surf pSurf = new Surf(pIplImage, ipts);
pSurf.getDescriptors(m_bUpright);
// Save algorithm-related data in the point.
TrackPointSURF tps = new TrackPointSURF(_x, _y, _t);
tps.FoundFeatures = ipts;
tps.SearchWindow = new Point(searchLeft, searchTop);
if (_previousPoints.Count == 0 || _manual)
{
// Find the closest point from the user's point.
int iClosest = -1;
double fBestDistance = double.MaxValue;
if (ipts.Count > 0)
{
Point userPoint = new Point(_x, _y);
for (int i = 0; i < ipts.Count; i++)
{
double fDistance = CalibrationHelper.PixelDistance(new PointF((float)_x, (float)_y), new PointF(ipts[i].x + searchLeft, ipts[i].y + searchTop));
if (fDistance < fBestDistance)
{
fBestDistance = fDistance;
iClosest = i;
}
}
tps.MatchedFeature = tps.FoundFeatures[iClosest];
tps.X = (int)(tps.MatchedFeature.x + searchLeft);
tps.Y = (int)(tps.MatchedFeature.y + searchTop);
log.Debug(String.Format("Initializing of the tracking. Closest feature to user's point : {0:0.00}", fBestDistance));
log.Debug(String.Format("Tracking result (init): [{0};{1}], user selection was: [{2};{3}]", tps.X, tps.Y, _x, _y));
}
else
{
// Ouch! The point selected by the user is in a no-feature zone.
tps = null;
log.Debug(String.Format("Tracking impossible from this point. Selected point is in No-feature zone."));
}
}
return(tps);
}
