Cv2FastNlMeansDenoising Method OpenCvSharp Class Library
Perform image denoising using Non-local Means Denoising algorithm with several computational optimizations. Noise expected to be a gaussian white noise

Namespace:  OpenCvSharp.CPlusPlus
Assembly:  OpenCvSharp.CPlusPlus (in OpenCvSharp.CPlusPlus.dll) Version: 1.0.0.0 (1.0.0.0)
Syntax

public static void FastNlMeansDenoising(
	InputArray src,
	OutputArray dst,
	float h = 3f,
	int templateWindowSize = 7,
	int searchWindowSize = 21
)

Parameters

src
Type: OpenCvSharp.CPlusPlusInputArray
Input 8-bit 1-channel, 2-channel or 3-channel image.
dst
Type: OpenCvSharp.CPlusPlusOutputArray
Output image with the same size and type as src .
h (Optional)
Type: SystemSingle
Parameter regulating filter strength. Big h value perfectly removes noise but also removes image details, smaller h value preserves details but also preserves some noise
templateWindowSize (Optional)
Type: SystemInt32
Size in pixels of the template patch that is used to compute weights. Should be odd. Recommended value 7 pixels
searchWindowSize (Optional)
Type: SystemInt32
Size in pixels of the window that is used to compute weighted average for given pixel. Should be odd. Affect performance linearly: greater searchWindowsSize - greater denoising time. Recommended value 21 pixels
See Also

Reference