Class used for extracting Speeded Up Robust Features (SURF) from an image. : More...

#include <opencv2/xfeatures2d/cuda.hpp>

Public Types
enum	KeypointLayout { X_ROW = 0, Y_ROW, LAPLACIAN_ROW, OCTAVE_ROW, SIZE_ROW, ANGLE_ROW, HESSIAN_ROW, ROWS_COUNT }

Public Member Functions
	SURF_CUDA ()
	the default constructor

	SURF_CUDA (double _hessianThreshold, int _nOctaves=4, int _nOctaveLayers=2, bool _extended=false, float _keypointsRatio=0.01f, bool _upright=false)
	the full constructor taking all the necessary parameters

int	defaultNorm () const
	returns the default norm type

int	descriptorSize () const
	returns the descriptor size in float's (64 or 128)

void	downloadDescriptors (const GpuMat &descriptorsGPU, std::vector< float > &descriptors)
	download descriptors from device to host memory

void	downloadKeypoints (const GpuMat &keypointsGPU, std::vector< KeyPoint > &keypoints)
	download keypoints from device to host memory

void	operator() (const GpuMat &img, const GpuMat &mask, GpuMat &keypoints)

void	operator() (const GpuMat &img, const GpuMat &mask, GpuMat &keypoints, GpuMat &descriptors, bool useProvidedKeypoints=false)

void	operator() (const GpuMat &img, const GpuMat &mask, std::vector< KeyPoint > &keypoints)

void	operator() (const GpuMat &img, const GpuMat &mask, std::vector< KeyPoint > &keypoints, GpuMat &descriptors, bool useProvidedKeypoints=false)

void	operator() (const GpuMat &img, const GpuMat &mask, std::vector< KeyPoint > &keypoints, std::vector< float > &descriptors, bool useProvidedKeypoints=false)

void	releaseMemory ()

void	uploadKeypoints (const std::vector< KeyPoint > &keypoints, GpuMat &keypointsGPU)
	upload host keypoints to device memory

Public Attributes
GpuMat	det

bool	extended

double	hessianThreshold

float	keypointsRatio
	max keypoints = min(keypointsRatio * img.size().area(), 65535)

GpuMat	mask1

GpuMat	maskSum

GpuMat	maxPosBuffer

int	nOctaveLayers

int	nOctaves

GpuMat	sum

GpuMat	trace

bool	upright

Detailed Description

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 Also: 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

Member Enumeration Documentation

enum cv::cuda::SURF_CUDA::KeypointLayout

Enumerator
X_ROW
Y_ROW
LAPLACIAN_ROW
OCTAVE_ROW
SIZE_ROW
ANGLE_ROW
HESSIAN_ROW
ROWS_COUNT

Constructor & Destructor Documentation

cv::cuda::SURF_CUDA::SURF_CUDA ( )

the default constructor

cv::cuda::SURF_CUDA::SURF_CUDA	(	double	_hessianThreshold,
		int	_nOctaves = `4`,
		int	_nOctaveLayers = `2`,
		bool	_extended = `false`,
		float	_keypointsRatio = `0.01f`,
		bool	_upright = `false`
	)

explicit

the full constructor taking all the necessary parameters

Member Function Documentation

int cv::cuda::SURF_CUDA::defaultNorm ( ) const

returns the default norm type

int cv::cuda::SURF_CUDA::descriptorSize ( ) const

returns the descriptor size in float's (64 or 128)

void cv::cuda::SURF_CUDA::downloadDescriptors	(	const GpuMat &	descriptorsGPU,
		std::vector< float > &	descriptors
	)

download descriptors from device to host memory

void cv::cuda::SURF_CUDA::downloadKeypoints	(	const GpuMat &	keypointsGPU,
		std::vector< KeyPoint > &	keypoints
	)

download keypoints from device to host memory

void cv::cuda::SURF_CUDA::operator()	(	const GpuMat &	img,
		const GpuMat &	mask,
		GpuMat &	keypoints
	)

finds the keypoints using fast hessian detector used in SURF supports CV_8UC1 images keypoints will have nFeature cols and 6 rows keypoints.ptr<float>(X_ROW)[i] will contain x coordinate of i'th feature keypoints.ptr<float>(Y_ROW)[i] will contain y coordinate of i'th feature keypoints.ptr<float>(LAPLACIAN_ROW)[i] will contain laplacian sign of i'th feature keypoints.ptr<float>(OCTAVE_ROW)[i] will contain octave of i'th feature keypoints.ptr<float>(SIZE_ROW)[i] will contain size of i'th feature keypoints.ptr<float>(ANGLE_ROW)[i] will contain orientation of i'th feature keypoints.ptr<float>(HESSIAN_ROW)[i] will contain response of i'th feature

void cv::cuda::SURF_CUDA::operator()	(	const GpuMat &	img,
		const GpuMat &	mask,
		GpuMat &	keypoints,
		GpuMat &	descriptors,
		bool	useProvidedKeypoints = `false`
	)

finds the keypoints and computes their descriptors. Optionally it can compute descriptors for the user-provided keypoints and recompute keypoints direction

void cv::cuda::SURF_CUDA::operator()	(	const GpuMat &	img,
		const GpuMat &	mask,
		std::vector< KeyPoint > &	keypoints
	)

void cv::cuda::SURF_CUDA::operator()	(	const GpuMat &	img,
		const GpuMat &	mask,
		std::vector< KeyPoint > &	keypoints,
		GpuMat &	descriptors,
		bool	useProvidedKeypoints = `false`
	)

void cv::cuda::SURF_CUDA::operator()	(	const GpuMat &	img,
		const GpuMat &	mask,
		std::vector< KeyPoint > &	keypoints,
		std::vector< float > &	descriptors,
		bool	useProvidedKeypoints = `false`
	)

void cv::cuda::SURF_CUDA::releaseMemory ( )

void cv::cuda::SURF_CUDA::uploadKeypoints	(	const std::vector< KeyPoint > &	keypoints,
		GpuMat &	keypointsGPU
	)

upload host keypoints to device memory

Member Data Documentation

GpuMat cv::cuda::SURF_CUDA::det

bool cv::cuda::SURF_CUDA::extended

double cv::cuda::SURF_CUDA::hessianThreshold

float cv::cuda::SURF_CUDA::keypointsRatio

max keypoints = min(keypointsRatio * img.size().area(), 65535)

GpuMat cv::cuda::SURF_CUDA::mask1

GpuMat cv::cuda::SURF_CUDA::maskSum

GpuMat cv::cuda::SURF_CUDA::maxPosBuffer

int cv::cuda::SURF_CUDA::nOctaveLayers

int cv::cuda::SURF_CUDA::nOctaves

GpuMat cv::cuda::SURF_CUDA::sum

GpuMat cv::cuda::SURF_CUDA::trace

bool cv::cuda::SURF_CUDA::upright

The documentation for this class was generated from the following file:

contrib/modules/xfeatures2d/include/opencv2/xfeatures2d/cuda.hpp

Public Types

Public Member Functions

Public Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation