Cv2FindContours Method (InputOutputArray, Mat, OutputArray, RetrievalModes, ContourApproximationModes, NullablePoint)

public static void FindContours(
	InputOutputArray image,
	out Mat[] contours,
	OutputArray hierarchy,
	RetrievalModes mode,
	ContourApproximationModes method,
	Nullable<Point> offset = null
)

Public Shared Sub FindContours ( 
	image As InputOutputArray,
	<OutAttribute> ByRef contours As Mat(),
	hierarchy As OutputArray,
	mode As RetrievalModes,
	method As ContourApproximationModes,
	Optional offset As Nullable(Of Point) = Nothing
)

public:
static void FindContours(
	InputOutputArray^ image, 
	[OutAttribute] array<Mat^>^% contours, 
	OutputArray^ hierarchy, 
	RetrievalModes mode, 
	ContourApproximationModes method, 
	Nullable<Point> offset = nullptr
)

static member FindContours : 
        image : InputOutputArray * 
        contours : Mat[] byref * 
        hierarchy : OutputArray * 
        mode : RetrievalModes * 
        method : ContourApproximationModes * 
        ?offset : Nullable<Point> 
(* Defaults:
        let _offset = defaultArg offset null
*)
-> unit 

Parameters

image

Type: OpenCvSharpInputOutputArray
Source, an 8-bit single-channel image. Non-zero pixels are treated as 1’s. Zero pixels remain 0’s, so the image is treated as binary. The function modifies the image while extracting the contours.

contours

Type: OpenCvSharpMat
Detected contours. Each contour is stored as a vector of points.

hierarchy

Type: OpenCvSharpOutputArray
Optional output vector, containing information about the image topology. It has as many elements as the number of contours. For each i-th contour contours[i], the members of the elements hierarchy[i] are set to 0-based indices in contours of the next and previous contours at the same hierarchical level, the first child contour and the parent contour, respectively. If for the contour i there are no next, previous, parent, or nested contours, the corresponding elements of hierarchy[i] will be negative.

mode

Type: OpenCvSharpRetrievalModes
Contour retrieval mode

method

Type: OpenCvSharpContourApproximationModes
Contour approximation method

offset (Optional)

Type: SystemNullablePoint
Optional 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.

Reference