Package org.opencv.xfeatures2d

Class SURF_CUDA

java.lang.Object
org.opencv.xfeatures2d.SURF_CUDA
public class SURF_CUDA extends Object
Class used for extracting Speeded Up Robust Features (SURF) from an image. : The class SURF_CUDA implements Speeded Up Robust Features descriptor. There is a fast multi-scale Hessian keypoint detector that can be used to find the keypoints (which is the default option). But the descriptors can also be computed for the user-specified keypoints. Only 8-bit grayscale images are supported. The class SURF_CUDA can store results in the GPU and CPU memory. It provides functions to convert results between CPU and GPU version ( uploadKeypoints, downloadKeypoints, downloadDescriptors ). The format of CPU results is the same as SURF results. GPU results are stored in GpuMat. The keypoints matrix is \(\texttt{nFeatures} \times 7\) matrix with the CV_32FC1 type.
  • keypoints.ptr<float>(X_ROW)[i] contains x coordinate of the i-th feature.
  • keypoints.ptr<float>(Y_ROW)[i] contains y coordinate of the i-th feature.
  • keypoints.ptr<float>(LAPLACIAN_ROW)[i] contains the laplacian sign of the i-th feature.
  • keypoints.ptr<float>(OCTAVE_ROW)[i] contains the octave of the i-th feature.
  • keypoints.ptr<float>(SIZE_ROW)[i] contains the size of the i-th feature.
  • keypoints.ptr<float>(ANGLE_ROW)[i] contain orientation of the i-th feature.
  • keypoints.ptr<float>(HESSIAN_ROW)[i] contains the response of the i-th feature.
The descriptors matrix is \(\texttt{nFeatures} \times \texttt{descriptorSize}\) matrix with the CV_32FC1 type. The class SURF_CUDA uses some buffers and provides access to it. All buffers can be safely released between function calls. SEE: SURF Note:
  • An example for using the SURF keypoint matcher on GPU can be found at opencv_source_code/samples/gpu/surf_keypoint_matcher.cpp

  • Field Details

  • Constructor Details

    • SURF_CUDA

      protected SURF_CUDA(long addr)

  • Method Details

    • getNativeObjAddr

      public long getNativeObjAddr()

    • __fromPtr__

      public static SURF_CUDA __fromPtr__(long addr)

    • create

      public static SURF_CUDA create(double _hessianThreshold, int _nOctaves, int _nOctaveLayers, boolean _extended, float _keypointsRatio, boolean _upright)
      Parameters:
      _hessianThreshold - Threshold for hessian keypoint detector used in SURF.
      _nOctaves - Number of pyramid octaves the keypoint detector will use.
      _nOctaveLayers - Number of octave layers within each octave.
      _extended - Extended descriptor flag (true - use extended 128-element descriptors; false - use 64-element descriptors).
      _keypointsRatio - Limits a maximum number of features
      _upright - Up-right or rotated features flag (true - do not compute orientation of features; false - compute orientation).
      Returns:
      automatically generated

    • create

      public static SURF_CUDA create(double _hessianThreshold, int _nOctaves, int _nOctaveLayers, boolean _extended, float _keypointsRatio)
      Parameters:
      _hessianThreshold - Threshold for hessian keypoint detector used in SURF.
      _nOctaves - Number of pyramid octaves the keypoint detector will use.
      _nOctaveLayers - Number of octave layers within each octave.
      _extended - Extended descriptor flag (true - use extended 128-element descriptors; false - use 64-element descriptors).
      _keypointsRatio - Limits a maximum number of features false - compute orientation).
      Returns:
      automatically generated

    • create

      public static SURF_CUDA create(double _hessianThreshold, int _nOctaves, int _nOctaveLayers, boolean _extended)
      Parameters:
      _hessianThreshold - Threshold for hessian keypoint detector used in SURF.
      _nOctaves - Number of pyramid octaves the keypoint detector will use.
      _nOctaveLayers - Number of octave layers within each octave.
      _extended - Extended descriptor flag (true - use extended 128-element descriptors; false - use 64-element descriptors). false - compute orientation).
      Returns:
      automatically generated

    • create

      public static SURF_CUDA create(double _hessianThreshold, int _nOctaves, int _nOctaveLayers)
      Parameters:
      _hessianThreshold - Threshold for hessian keypoint detector used in SURF.
      _nOctaves - Number of pyramid octaves the keypoint detector will use.
      _nOctaveLayers - Number of octave layers within each octave. 64-element descriptors). false - compute orientation).
      Returns:
      automatically generated

    • create

      public static SURF_CUDA create(double _hessianThreshold, int _nOctaves)
      Parameters:
      _hessianThreshold - Threshold for hessian keypoint detector used in SURF.
      _nOctaves - Number of pyramid octaves the keypoint detector will use. 64-element descriptors). false - compute orientation).
      Returns:
      automatically generated

    • create

      public static SURF_CUDA create(double _hessianThreshold)
      Parameters:
      _hessianThreshold - Threshold for hessian keypoint detector used in SURF. 64-element descriptors). false - compute orientation).
      Returns:
      automatically generated

    • descriptorSize

      public int descriptorSize()

    • defaultNorm

      public int defaultNorm()

    • get_hessianThreshold

      public double get_hessianThreshold()

    • get_nOctaves

      public int get_nOctaves()

    • get_nOctaveLayers

      public int get_nOctaveLayers()

    • get_extended

      public boolean get_extended()

    • get_upright

      public boolean get_upright()

    • get_keypointsRatio

      public float get_keypointsRatio()

    • finalize

      protected void finalize() throws Throwable
      Overrides:
      finalize in class Object
      Throws:
      Throwable