CCD camera nonlinearity degree calibration method based on structured light three-dimensional measurement system

Abstract

The invention provides a CCD camera nonlinearity degree calibration method based on a structured light three-dimensional measurement system. The method comprises the steps that according to the measurement processes of the structured light three-dimensional measurement system, on the basis that a series of standard images which are projected by a projector and accord with linear distribution are collected, a standard image gray scale-camera collected image gray scale distribution curve is drawn after certain data processing so as to further calculate the nonlinearity degree of a CCD camera; because gray scale gradient is small when the standard images are grouped, and the number of images collected by the CCD camera is large, random errors are reduced, and nonlinearity degree measurement precision is improved; the CCD camera nonlinearity degree calibration method based on the structured light three-dimensional measurement system accords with conditions of the structured light three-dimensional measurement system, and is simple in calibration process, less in middle link, and accurate in nonlinearity degree calibration result.

Description

technical field [0001] The invention belongs to the field of optical measurement, and relates to a method for calibrating the nonlinearity of a CCD camera in an optical measurement system, in particular to a method for calibrating the nonlinearity of a CCD camera based on a structured light three-dimensional measurement system. Background technique [0002] Optical 3D measurement is widely used in many fields such as industrial automatic inspection, product quality control, reverse design, biomedicine, virtual reality, cultural relic reproduction, anthropometric measurement, etc. This huge application demand has prompted the rapid development of various optical measurement technologies. With the development of computer technology, digital image acquisition equipment and optical devices, many 3D optical measurement technologies have entered the mature stage of commercial application, and new 3D measurement methods are still emerging. Structured light three-dimensional measur...

AI Technical Summary

Problems solved by technology

Corresponding to the structured light 3D measurement system, there is currently no accurate and suitable CCD nonlinearity calibration method; the existing methods have great defects in the structured light 3D measurement system, for example, the existing method needs to use a specific light source, but the specific The light source cannot project structured light like the projector in the optical measurement system, and the experimental environment of the specific light source is demanding and expensive, which is not suitable for optical measurement; The cold spot increases the nonlinearity; and the CCD element is greatly affected by random noise, and there are random errors in image acquisition, and the system to be tested also has random errors. The number of image acquisitions in the existing method is small, and it is difficult to suppress random errors

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