Emgu CV Library Documentation
cvFindContours Method (image, storage, firstContour, headerSize, mode, method, offset)
NamespacesEmgu.CVCvInvokecvFindContours(IntPtr, IntPtr, IntPtr%, Int32, RETR_TYPE, CHAIN_APPROX_METHOD, MCvPoint)

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Retrieves contours from the binary image and returns the number of retrieved contours. The pointer first_contour is filled by the function. It will contain pointer to the first most outer contour or NULL if no contours is detected (if the image is completely black). Other contours may be reached from first_contour using h_next and v_next links. The sample in cvDrawContours discussion shows how to use contours for connected component detection. Contours can be also used for shape analysis and object recognition - see squares.c in OpenCV sample directory
Declaration Syntax
C#Visual BasicVisual C++
public static int cvFindContours(
	IntPtr image,
	IntPtr storage,
	ref IntPtr firstContour,
	int headerSize,
	RETR_TYPE mode,
	CHAIN_APPROX_METHOD method,
	MCvPoint offset
)
Public Shared Function cvFindContours ( _
	image As IntPtr, _
	storage As IntPtr, _
	ByRef firstContour As IntPtr, _
	headerSize As Integer, _
	mode As RETR_TYPE, _
	method As CHAIN_APPROX_METHOD, _
	offset As MCvPoint _
) As Integer
public:
static int cvFindContours(
	IntPtr image, 
	IntPtr storage, 
	IntPtr% firstContour, 
	int headerSize, 
	RETR_TYPE mode, 
	CHAIN_APPROX_METHOD method, 
	MCvPoint offset
)
Parameters
image (IntPtr)
The source 8-bit single channel image. Non-zero pixels are treated as 1s, zero pixels remain 0s - that is image treated as binary. To get such a binary image from grayscale, one may use cvThreshold, cvAdaptiveThreshold or cvCanny. The function modifies the source image content
storage (IntPtr)
Container of the retrieved contours
firstContour ( IntPtr %)
Output parameter, will contain the pointer to the first outer contour
headerSize (Int32)
Size of the sequence header, >=sizeof(CvChain) if method=CV_CHAIN_CODE, and >=sizeof(CvContour) otherwise
mode (RETR_TYPE)
Retrieval mode
method (CHAIN_APPROX_METHOD)
Approximation method (for all the modes, except CV_RETR_RUNS, which uses built-in approximation).
offset (MCvPoint)
Offset, by which every contour point is shifted. This is useful if the contours are extracted from the image ROI and then they should be analyzed in the whole image context
Return Value

[Missing <returns> documentation for M:Emgu.CV.CvInvoke.cvFindContours(System.IntPtr,System.IntPtr,System.IntPtr@,System.Int32,Emgu.CV.CvEnum.RETR_TYPE,Emgu.CV.CvEnum.CHAIN_APPROX_METHOD,Emgu.CV.MCvPoint)]

Assembly: Emgu.CV (Module: Emgu.CV) Version: 1.3.0.0 (1.3.0.0)