/// <summary>
 /// Create an OpenCL SURF detector
 /// </summary>
 /// <param name="hessianThreshold">The interest operator threshold. Use 100 for default</param>
 /// <param name="nOctaves">The number of octaves to process. Use 4 for default</param>
 /// <param name="nIntervals">The number of intervals in each octave. Use 4 for default</param>
 /// <param name="extended">True, if generate 128-len descriptors, false - 64-len descriptors. Use true for default.</param>
 /// <param name="featuresRatio">Max features = featuresRatio * img.size().srea(). Use 0.01 for default</param>
 /// <param name="upright">Use false for default. If set to true, the orientation is not computed for the keypoints</param>
 public OclSURFDetector(
     float hessianThreshold,
     int nOctaves,
     int nIntervals,
     bool extended,
     float featuresRatio,
     bool upright)
 {
     _ptr = OclInvoke.oclSURFDetectorCreate(hessianThreshold, nOctaves, nIntervals, extended, featuresRatio, upright);
 }