public void ExtractSURF(
	CvArr mask,
	ref CvSeq<CvSURFPoint> keypoints,
	out CvSeq<IntPtr> descriptors,
	CvMemStorage storage,
	CvSURFParams param,
	bool useProvidedKeyPts
)

Public Sub ExtractSURF ( 
	mask As CvArr,
	ByRef keypoints As CvSeq(Of CvSURFPoint),
	<OutAttribute> ByRef descriptors As CvSeq(Of IntPtr),
	storage As CvMemStorage,
	param As CvSURFParams,
	useProvidedKeyPts As Boolean
)

public:
void ExtractSURF(
	CvArr^ mask, 
	CvSeq<CvSURFPoint>^% keypoints, 
	[OutAttribute] CvSeq<IntPtr>^% descriptors, 
	CvMemStorage^ storage, 
	CvSURFParams^ param, 
	bool useProvidedKeyPts
)

member ExtractSURF : 
        mask : CvArr * 
        keypoints : CvSeq<CvSURFPoint> byref * 
        descriptors : CvSeq<IntPtr> byref * 
        storage : CvMemStorage * 
        param : CvSURFParams * 
        useProvidedKeyPts : bool -> unit 

Parameters

mask

Type: OpenCvSharpCvArr
The optional input 8-bit mask. The features are only found in the areas that contain more than 50% of non-zero mask pixels.

keypoints

Type: OpenCvSharpCvSeqCvSURFPoint
The output parameter; double pointer to the sequence of keypoints. This will be the sequence of CvSURFPoint structures.

descriptors

Type: OpenCvSharpCvSeqIntPtr
The optional output parameter; double pointer to the sequence of descriptors; Depending on the params.extended value, each element of the sequence will be either 64-element or 128-element floating-point (CV_32F) vector. If the parameter is null, the descriptors are not computed.

storage

Type: OpenCvSharpCvMemStorage
Memory storage where keypoints and descriptors will be stored.

param

Type: OpenCvSharpCvSURFParams
Various algorithm parameters put to the structure CvSURFParams

useProvidedKeyPts

Type: SystemBoolean
If useProvidedKeyPts!=0, keypoints are not detected, but descriptors are computed at the locations provided in keypoints (a CvSeq of CvSURFPoint).

Reference