Cv2Flip Method OpenCvSharp Class Library
reverses the order of the rows, columns or both in a matrix

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

public static void Flip(
	InputArray src,
	OutputArray dst,
	FlipMode flipCode
)

Parameters

src
Type: OpenCvSharp.CPlusPlusInputArray
The source array
dst
Type: OpenCvSharp.CPlusPlusOutputArray
The destination array; will have the same size and same type as src
flipCode
Type: OpenCvSharpFlipMode
Specifies how to flip the array: 0 means flipping around the x-axis, positive (e.g., 1) means flipping around y-axis, and negative (e.g., -1) means flipping around both axes. See also the discussion below for the formulas.
See Also

Reference