public static extern void cvExtractSURF( IntPtr image, IntPtr mask, ref IntPtr keypoints, ref IntPtr descriptors, IntPtr storage, SurfDetector parameters, int useProvidedKeyPoints);
public DetectorResult Process(Image<Bgr, byte> rawFrame, Image<Gray, byte> grayFrame)
{
var surfParam = new SurfDetector(900, true);
var modelImage = new Image<Gray, byte>("iphone\\signin.jpg");
var modelFeatures = surfParam.DetectFeatures(modelImage, null);
var tracker = new Features2DTracker(modelFeatures);
var imageFeatures = surfParam.DetectFeatures(grayFrame, null);
var homographyMatrix = tracker.Detect(imageFeatures, 100.0);
Image<Bgr, Byte> processedImage = modelImage.Convert<Bgr, Byte>().ConcateVertical(rawFrame);
if (homographyMatrix != null)
{
var rect = modelImage.ROI;
var pts = new[]
{
new PointF(rect.Left, rect.Bottom),
new PointF(rect.Right, rect.Bottom),
new PointF(rect.Right, rect.Top),
new PointF(rect.Left, rect.Top)
};
homographyMatrix.ProjectPoints(pts);
for (int i = 0; i < pts.Length; i++)
pts[i].Y += modelImage.Height;
processedImage.DrawPolyline(Array.ConvertAll(pts, Point.Round), true, new Bgr(Color.DarkOrange), 1);
}
return new DetectorResult(){RawImage = rawFrame, ProcessedImage = processedImage};
}
/// <summary>
/// Create a MCvSURFParams using the specific values
/// </summary>
/// <param name="hessianThresh">
/// Only features with keypoint.hessian larger than that are extracted.
/// good default value is ~300-500 (can depend on the average local contrast and sharpness of the image).
/// user can further filter out some features based on their hessian values and other characteristics
/// </param>
/// <param name="extendedFlag">
/// false means basic descriptors (64 elements each),
/// true means extended descriptors (128 elements each)
/// </param>
public SurfDetector(double hessianThresh, bool extendedFlag)
{
SurfDetector p = CvInvoke.cvSURFParams(hessianThresh, extendedFlag ? 1 : 0);
extended = p.extended;
hessianThreshold = p.hessianThreshold;
nOctaves = p.nOctaves;
nOctaveLayers = p.nOctaveLayers;
}
private static extern void CvSURFDetectorDetectKeyPoints( ref SurfDetector detector, IntPtr image, IntPtr mask, IntPtr keypoints);
private static extern void CvSURFDetectorDetectFeature( ref SurfDetector detector, IntPtr image, IntPtr mask, IntPtr keypoints, IntPtr descriptors);
private static extern void CvSURFDetectorComputeDescriptors( ref SurfDetector detector, IntPtr image, IntPtr mask, IntPtr keypoints, IntPtr descriptors);
private extern static void CvSURFDetectorComputeDescriptors(
ref SurfDetector detector,
IntPtr image,
IntPtr mask,
IntPtr keypoints,
IntPtr descriptors);
private extern static void CvSURFDetectorDetectFeature(
ref SurfDetector detector,
IntPtr image,
IntPtr mask,
IntPtr keypoints,
IntPtr descriptors);
private extern static void CvSURFDetectorDetectKeyPoints(
ref SurfDetector detector,
IntPtr image,
IntPtr mask,
IntPtr keypoints);