OpenCV  4.1.0 Open Source Computer Vision

## Functions

double cv::sfm::depth (InputArray R, InputArray t, InputArray X)
Returns the depth of a point transformed by a rigid transform.

void cv::sfm::euclideanToHomogeneous (InputArray src, OutputArray dst)
Converts points from Euclidean to homogeneous space. E.g., ((x,y)->(x,y,1))

void cv::sfm::homogeneousToEuclidean (InputArray src, OutputArray dst)
Converts point coordinates from homogeneous to euclidean pixel coordinates. E.g., ((x,y,z)->(x/z, y/z))

void cv::sfm::KRtFromProjection (InputArray P, OutputArray K, OutputArray R, OutputArray t)
Get K, R and t from projection matrix P, decompose using the RQ decomposition.

void cv::sfm::projectionFromKRt (InputArray K, InputArray R, InputArray t, OutputArray P)
Get projection matrix P from K, R and t.

## Function Documentation

 double cv::sfm::depth ( InputArray R, InputArray t, InputArray X )

Returns the depth of a point transformed by a rigid transform.

Parameters
 R Input 3x3 rotation matrix. t Input 3x1 translation vector. X Input 3x1 or 4x1 vector with the 3d point.
 void cv::sfm::euclideanToHomogeneous ( InputArray src, OutputArray dst )

Converts points from Euclidean to homogeneous space. E.g., ((x,y)->(x,y,1))

Parameters
 src Input vector of N-dimensional points. dst Output vector of N+1-dimensional points.
 void cv::sfm::homogeneousToEuclidean ( InputArray src, OutputArray dst )

Converts point coordinates from homogeneous to euclidean pixel coordinates. E.g., ((x,y,z)->(x/z, y/z))

Parameters
 src Input vector of N-dimensional points. dst Output vector of N-1-dimensional points.
 void cv::sfm::KRtFromProjection ( InputArray P, OutputArray K, OutputArray R, OutputArray t )

Get K, R and t from projection matrix P, decompose using the RQ decomposition.

Parameters
 P Input 3x4 projection matrix. K Output 3x3 camera matrix $$K = \vecthreethree{f_x}{0}{c_x}{0}{f_y}{c_y}{0}{0}{1}$$. R Output 3x3 rotation matrix. t Output 3x1 translation vector.

Reference:HartleyZ00 A4.1.1 pag.579

 void cv::sfm::projectionFromKRt ( InputArray K, InputArray R, InputArray t, OutputArray P )

Get projection matrix P from K, R and t.

Parameters
 K Input 3x3 camera matrix $$K = \vecthreethree{f_x}{0}{c_x}{0}{f_y}{c_y}{0}{0}{1}$$. R Input 3x3 rotation matrix. t Input 3x1 translation vector. P Output 3x4 projection matrix.

This function estimate the projection matrix by solving the following equation: $$P = K * [R|t]$$