disparity_to_distance — Transform a disparity value into a distance value in a rectified binocular stereo system.
disparity_to_distance transforms a disparity value into a distance of an object point to the binocular stereo system. The cameras of this system must be rectified and are defined by the rectified internal parameters CamParamRect1 of camera 1 and CamParamRect2 of camera 2, and the external parameters RelPoseRect. Latter specifies the relative pose of both cameras to each other by defining a point transformation from rectified camera system 2 to rectified camera system 1. These parameters can be obtained from the operator calibrate_cameras and gen_binocular_rectification_map. The disparity value Disparity is defined by the column difference of the image coordinates of two corresponding points on an epipolar line according to the equation (see also binocular_disparity). This value characterises a set of 3D object points of an equal distance to a plane being parallel to the rectified image plane of the stereo system. The distance to the subset plane z=0 which is parallel to the rectified image plane and contains the optical centers of both cameras is returned in Distance.
If using cameras with telecentric lenses, the Distance is not defined as the distance of a point to the camera but as the distance from the point to the plane, defined by the y-axes of both cameras and their baseline (see gen_binocular_rectification_map).
For a stereo setup of mixed type (i.e., for a stereo setup in which one of the original cameras is a perspective camera and the other camera is a telecentric camera; see gen_binocular_rectification_map), the rectifying plane of the two cameras is in a position with respect to the object that would lead to very unintuitive distances. Therefore, disparity_to_distance does not support stereo setups of mixed type. For stereo setups of mixed type, disparity_to_point_3d should be used instead.
Rectified internal camera parameters of camera 1.
Rectified internal camera parameters of camera 2.
Point transformation from the rectified camera 2 to the rectified camera 1.
Number of elements: 7
Disparity between the images of the world point.
Distance of a world point to the rectified camera system.
disparity_to_distance returns 2 (H_MSG_TRUE) if all parameter values are correct. If necessary, an exception is raised.
binocular_calibration, gen_binocular_rectification_map, map_image, binocular_disparity