Returns the new camera matrix based on the free scaling parameter

cameraMatrix = cv.getOptimalNewCameraMatrix(cameraMatrix, distCoeffs, imageSize)
[cameraMatrix, validPixROI] = cv.getOptimalNewCameraMatrix(...)
[...] = cv.getOptimalNewCameraMatrix(..., 'OptionName', optionValue, ...)

Input

• cameraMatrix Input 3x3 camera matrix, A = [fx 0 cx; 0 fy cy; 0 0 1].
• distCoeffs Input vector of distortion coefficients [k1,k2,p1,p2,k3,k4,k5,k6,s1,s2,s3,s4,taux,tauy] of 4, 5, 8, 12 or 14 elements. If the vector is empty, the zero distortion coefficients are assumed.
• imageSize Original image size [w,h].

Output

• cameraMatrix Output new camera matrix, 3x3.
• validPixROI Optional output rectangle [x,y,w,h] that outlines all-good-pixels region in the undistorted image. See roi1, roi2 description in cv.stereoRectify.

Options

• Alpha Free scaling parameter between 0 (when all the pixels in the undistorted image are valid) and 1 (when all the source image pixels are retained in the undistorted image). See cv.stereoRectify for details. default 0.8
• NewImageSize Image size after rectification [w,h]. By default, it is set to imageSize.
• CenterPrincipalPoint Optional flag that indicates whether in the new camera matrix the principal point should be at the image center or not. By default, the principal point is chosen to best fit a subset of the source image (determined by Alpha) to the corrected image. default false.

The function computes and returns the optimal new camera matrix based on the free scaling parameter. By varying this parameter, you may retrieve only sensible pixels Alpha=0, keep all the original image pixels if there is valuable information in the corners Alpha=1, or get something in between. When Alpha>0, the undistortion result is likely to have some black pixels corresponding to "virtual" pixels outside of the captured distorted image. The original camera matrix, distortion coefficients, the computed new camera matrix, and newImageSize should be passed to cv.initUndistortRectifyMap to produce the maps for cv.remap.