Iterative phase correction method for low-quality stripe image

Abstract

The invention belongs to the field of optical measurement, and particularly discloses an iterative phase correction method for a low-quality stripe image. The method comprises the following steps of projecting a phase shift stripe image, shooting and decoding to obtain an initial phase, projecting the initial phase to an image brightness space, and obtaining a phase projection stripe image of thecurrent iteration period on the basis, conducting Gaussian filtering to acquire a Gaussian filtering phase of a current iteration period, judging whether an error between the Gaussian filtering phaseof the current iteration period and the Gaussian filtering phase of the previous iteration period is smaller than or equal to a preset threshold value or not, and if yes, outputting the Gaussian filtering phase, and if not, projecting the phase to an image brightness space for iteration. According to the method, the phase is projected to the image brightness space to obtain the stripe image underthe uniform reflectivity, the influence of Gaussian noise is suppressed, iterative filtering is performed on the stripe image to eliminate the influence of the object surface reflectivity and the light source nonlinear brightness, and thus high-precision phase recovery of the low-quality stripe image is realized.

Description

technical field [0001] The invention belongs to the technical field related to optical measurement, and more specifically, relates to an iterative phase correction method for low-quality fringe images. Background technique [0002] Optical 3D measurement methods, such as structured light and phase deflection, play an increasingly important role in modern manufacturing. Among them, the phase shift technology is a bridge connecting the measured object and the sensor. The accuracy of phase recovery directly determines the measurement accuracy of optical measurement methods. Generally speaking, there are three main factors that affect the accuracy of phase recovery: 1. The quality of phase shift fringe images obtained; 2. The number of phase shift steps; 3. Brightness modulation parameters. Wherein, as the number of phase shift steps increases, the number of phase shift images to be projected also increases, and the measurement speed decreases accordingly. The parameter of br...

AI Technical Summary

Problems solved by technology

Therefore, when filtering the fringe image of an object with a large reflectivity change, it will be affected by the surface reflectivity and cause distortion

And a significant drawback of high dynamic range imaging technology is the large number of projected pictures, which leads to slow measurement speed

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