Three-dimensional reconstruction from the method of CAD-based photogrammetry

Abstract

The three-dimensional (3D) reconstruction has become a hot research field of Photogrammetry and computer vision. This paper presents a measurement method of CAD-based Photogrammetry to do 3D reconstruction. CAD models and images which the exterior orientation is known are used. The visible edges of a volumetric CAD model with an initial pose are projected back into images after a hidden line analysis. This analysis determines which edges (or parts of edges) of the object are visible, and computes the edges of the object. Observation equations are formulated that establish the relationship between the parameterized CAD models and position of the edges in the images. The flow of this paper is as fellows. Firstly, parameterized CAD models are used to describe 3D objects, object models can be described in various ways, and this paper uses CSG models combined with B-rep. Secondly, fitting models to images. Manually select an appropriate model and approximate parameters, the parameterized models are projected back into the images, and then compute the optimal fitting automatically. Thirdly, calculate the parameters of the model. Experiments were done to box, sphere and column, which are the base primitive of some objects. The results of these experiments show that the method used in this paper are effective and have high precision. All primitives used in these experiments are well reconstructed.