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Cv2CalcOpticalFlowFarneback Method

Computes a dense optical flow using the Gunnar Farneback's algorithm.

Namespace:  OpenCvSharp
Assembly:  OpenCvSharp (in OpenCvSharp.dll) Version: 1.0.0
Syntax
public static void CalcOpticalFlowFarneback(
	InputArray prev,
	InputArray next,
	InputOutputArray flow,
	double pyrScale,
	int levels,
	int winsize,
	int iterations,
	int polyN,
	double polySigma,
	OpticalFlowFlags flags
)

Parameters

prev
Type: OpenCvSharpInputArray
first 8-bit single-channel input image.
next
Type: OpenCvSharpInputArray
second input image of the same size and the same type as prev.
flow
Type: OpenCvSharpInputOutputArray
computed flow image that has the same size as prev and type CV_32FC2.
pyrScale
Type: SystemDouble
parameter, specifying the image scale (<1) to build pyramids for each image; pyrScale=0.5 means a classical pyramid, where each next layer is twice smaller than the previous one.
levels
Type: SystemInt32
number of pyramid layers including the initial image; levels=1 means that no extra layers are created and only the original images are used.
winsize
Type: SystemInt32
averaging window size; larger values increase the algorithm robustness to image noise and give more chances for fast motion detection, but yield more blurred motion field.
iterations
Type: SystemInt32
number of iterations the algorithm does at each pyramid level.
polyN
Type: SystemInt32
size of the pixel neighborhood used to find polynomial expansion in each pixel; larger values mean that the image will be approximated with smoother surfaces, yielding more robust algorithm and more blurred motion field, typically poly_n =5 or 7.
polySigma
Type: SystemDouble
standard deviation of the Gaussian that is used to smooth derivatives used as a basis for the polynomial expansion; for polyN=5, you can set polySigma=1.1, for polyN=7, a good value would be polySigma=1.5.
flags
Type: OpenCvSharpOpticalFlowFlags
operation flags that can be a combination of OPTFLOW_USE_INITIAL_FLOW and/or OPTFLOW_FARNEBACK_GAUSSIAN
See Also