Computes the rectification transformations for 3-head camera, where all the heads are on the same line

S = cv.rectify3Collinear(cameraMatrix1, distCoeffs1, cameraMatrix2,
        distCoeffs2, cameraMatrix3, distCoeffs3, imageSize, R12, T12, R13, T13)
[...] = cv.rectify3Collinear(..., 'OptionName', optionValue, ...)

Input

• cameraMatrix1 First camera matrix 3x3.
• distCoeffs1 First camera distortion parameters of 4, 5, 8, 12 or 14 elements.
• cameraMatrix2 Second camera matrix 3x3.
• distCoeffs2 Second camera distortion parameters of 4, 5, 8, 12 or 14 elements.
• cameraMatrix3 Third camera matrix 3x3.
• distCoeffs3 Third camera distortion parameters of 4, 5, 8, 12 or 14 elements.
• imageSize Size of the image used for stereo calibration [w,h].
• R12 Rotation matrix between the coordinate systems of the first and the second cameras, 3x3/3x1 (see cv.Rodrigues)
• T12 Translation vector between coordinate systems of the first and the second cameras, 3x1.
• R13 Rotation matrix between the coordinate systems of the first and the third cameras, 3x3/3x1 (see cv.Rodrigues)
• T13 Translation vector between coordinate systems of the first and the third cameras, 3x1.

Output

• S scalar struct having the following fields:
  • R1 3x3 rectification transform (rotation matrix) for the first camera.
  • R2 3x3 rectification transform (rotation matrix) for the second camera.
  • R3 3x3 rectification transform (rotation matrix) for the third camera.
  • P1 3x4 projection matrix in the new (rectified) coordinate systems for the first camera.
  • P2 3x4 projection matrix in the new (rectified) coordinate systems for the second camera.
  • P3 3x4 projection matrix in the new (rectified) coordinate systems for the third camera.
  • Q 4x4 disparity-to-depth mapping matrix (see cv.reprojectImageTo3D).
  • roi1, roi2 rectangles inside the rectified images where all the pixels are valid [x,y,w,h]. If Alpha=0, the ROIs cover the whole images. Otherwise, they are likely to be smaller.
  • ratio disparity ratio, floating-point numeric scalar.

Options

• ImgPoints1, ImgPoints3 Optional cell arrays of 2D points {[x,y], ...}, used to adjust the third matrix P3. Not set by default.
• Alpha Free scaling parameter. If it is -1 or absent, the function performs the default scaling. Otherwise, the parameter should be between 0 and 1. Alpha=0 means that the rectified images are zoomed and shifted so that only valid pixels are visible (no black areas after rectification). Alpha=1 means that the rectified image is decimated and shifted so that all the pixels from the original iamges from the cameras are retained in the rectified images (no source image pixels are lost). Obviously, any intermediate value yields an intermediate result between those two extreme cases. default -1
• NewImageSize New image resolution after rectification. The same size should be passed to cv.initUndistortRectifyMap. When [0,0] is passed (default), it is set to the original imageSize. Setting it to larger value can help you preserve details in the original image, especially when there is a big radial distortion.
• ZeroDisparity If the flag is set, the function makes the principal points of each camera have the same pixel coordinates in the rectified views. And if the flag is not set, the function may still shift the images in the horizontal or vertical direction (depending on the orientation of epipolar lines) to maximize the useful image area. default true.