Scale Restoration of 3D Models Based on Camera Imaging Principle

In this paper, a method of 3D model scale restoration based on camera imaging principle is proposed. Firstly, a point-based 3D reconstruction method is used to reconstruct the measured object to obtain a 3D model. Then, two corner points are selected in the three-dimensional model, and their connection is perpendicular to the ground, and the Euclidean distance between the two corner points is calculated. The position of two corner points in a series of images taken from far to near the object to be measured is marked and the pixel distance in the image is calculated. The actual distance between two corner points is calculated according to the formula derived by the camera imaging principle in this paper. The ratio between the real world and the three-dimensional space of the model is obtained by comparing the actual distance with the distance in the three-dimensional space. Finally, the dimensional information of the three-dimensional model can be recovered by the Euclidean distance and the ratio of any two points in the model. The method is validated by experiments, and has certain engineering significance for the scale restoration of 3D model based on 3D reconstruction.