Model-based pose estimation

Question

I would like to estimate the pose of know 3D object by using opencv. I can use solvePnP if the points of the 3D Model and their corresponded points at the image are given. My question is: how I can find the correspondence between the know 3D Model and its projection on the image? Thank you a lot

Answer 1

Once you have some matches of points in the 3d model and points in the scene, you have to apply cv::findHomography(). This function calculates a matrix that projects any point from the 3D model into the scene. Actually only 4 matches are needed for homography calculation.