Function opencv::calib3d::init_inverse_rectification_map[−][src]

pub fn init_inverse_rectification_map(
    camera_matrix: &dyn ToInputArray, 
    dist_coeffs: &dyn ToInputArray, 
    r: &dyn ToInputArray, 
    new_camera_matrix: &dyn ToInputArray, 
    size: Size, 
    m1type: i32, 
    map1: &mut dyn ToOutputArray, 
    map2: &mut dyn ToOutputArray
) -> Result<()>
Expand description

Computes the projection and inverse-rectification transformation map. In essense, this is the inverse of #initUndistortRectifyMap to accomodate stereo-rectification of projectors (‘inverse-cameras’) in projector-camera pairs.

The function computes the joint projection and inverse rectification transformation and represents the result in the form of maps for #remap. The projected image looks like a distorted version of the original which, once projected by a projector, should visually match the original. In case of a monocular camera, newCameraMatrix is usually equal to cameraMatrix, or it can be computed by #getOptimalNewCameraMatrix for a better control over scaling. In case of a projector-camera pair, newCameraMatrix is normally set to P1 or P2 computed by #stereoRectify .

The projector is oriented differently in the coordinate space, according to R. In case of projector-camera pairs, this helps align the projector (in the same manner as #initUndistortRectifyMap for the camera) to create a stereo-rectified pair. This allows epipolar lines on both images to become horizontal and have the same y-coordinate (in case of a horizontally aligned projector-camera pair).

The function builds the maps for the inverse mapping algorithm that is used by #remap. That is, for each pixel inline formula in the destination (projected and inverse-rectified) image, the function computes the corresponding coordinates in the source image (that is, in the original digital image). The following process is applied:

block formula where inline formula are the distortion coefficients vector distCoeffs.

In case of a stereo-rectified projector-camera pair, this function is called for the projector while #initUndistortRectifyMap is called for the camera head. This is done after #stereoRectify, which in turn is called after #stereoCalibrate. If the projector-camera pair is not calibrated, it is still possible to compute the rectification transformations directly from the fundamental matrix using #stereoRectifyUncalibrated. For the projector and camera, the function computes homography H as the rectification transformation in a pixel domain, not a rotation matrix R in 3D space. R can be computed from H as block formula where cameraMatrix can be chosen arbitrarily.

Parameters

  • cameraMatrix: Input camera matrix inline formula .
  • distCoeffs: Input vector of distortion coefficients inline formula of 4, 5, 8, 12 or 14 elements. If the vector is NULL/empty, the zero distortion coefficients are assumed.
  • R: Optional rectification transformation in the object space (3x3 matrix). R1 or R2, computed by #stereoRectify can be passed here. If the matrix is empty, the identity transformation is assumed.
  • newCameraMatrix: New camera matrix inline formula.
  • size: Distorted image size.
  • m1type: Type of the first output map. Can be CV_32FC1, CV_32FC2 or CV_16SC2, see #convertMaps
  • map1: The first output map for #remap.
  • map2: The second output map for #remap.