A light-field camera calibration method for three-dimensional shape measurement

Abstract

The invention provides a light field camera calibration method for three-dimensional shape measurement, which calibrates calibration plates at different positions in space and corresponding light field original images, and obtains the corresponding relationship between light field parallax images and three-dimensional space information; Use the light field camera to shoot multiple defocused soft light pure color calibration plates to obtain the light field white image; calculate the devignetting matrix according to the light field camera white image; and iteratively calculate the light field camera microlens sub-pixel center coordinate matrix; the light field The camera shoots multiple dot calibration plates with known three-dimensional space positions and performs devignetting processing; establishes a light field mathematical model from three-dimensional coordinates to parallax, and calculates it according to the three-dimensional imaging law of the light field and the three-dimensional space information of the dots Obtaining the coordinates of the center of the dot and the parallax value corresponding to the dot calibration The present invention can efficiently and accurately convert the light field parallax image into three-dimensional space information without main lens distortion.

Description

technical field [0001] The invention relates to the technical field of three-dimensional shape measurement, in particular to a light field camera calibration method for three-dimensional shape measurement. Background technique [0002] Three-dimensional shape measurement technology is a core technology in the field of machine vision and measurement. Three-dimensional shape measurement refers to the measurement of three-dimensional information on the surface of an object. In recent years, the emergence of light field cameras provides a new solution direction for 3D shape measurement. The biggest difference between a light field camera and a traditional two-dimensional camera is that a microlens array is added in front of the sensor, so that it can record the propagation direction of light in space, thereby forming a special original light field image, and processing the light field image After rendering, light field multi-view images, light field refocusing images and light...

AI Technical Summary

Problems solved by technology

At present, the light field depth estimation algorithm usually only calculates the disparity map, and few people study the process of converting the disparity map into real 3D information, that is, there is no calibration method or algorithm for converting the disparity map into 3D topography in the prior art

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