/// <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 MCvSURFParams(double hessianThresh, bool extendedFlag)
{
MCvSURFParams p = CvInvoke.cvSURFParams(hessianThresh, extendedFlag ? 1 : 0);
extended = p.extended;
hessianThreshold = p.hessianThreshold;
nOctaves = p.nOctaves;
nOctaveLayers = p.nOctaveLayers;
}