Local blur analysis and phase error correction method for fringe projection profilometry systems

Rao, Li; Da, Feipeng

doi:10.1364/ao.57.004267

Cited by 31 publications

(8 citation statements)

References 17 publications

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“…After comprehensive consideration, the multi-frequency heterodyne principle was chosen for phase calculation, thanks to its good stability and accuracy. This principle superimposes two phase functions with different frequencies into a phase function with lower frequency, and combines the merits of three-frequency unwrapping and heterodyne method, namely, high measuring efficiency and excellent phase unwrapping accuracy [14][15][16]. The phase principal value p12 can be calculated by:…”

Section: Analysis Of Wrapped Phase and Dephasing Algorithmmentioning

confidence: 99%

Three-Dimensional Mirror Surface Measurement Based on Local Blur Analysis of Phase Measuring Deflectometry System

Sun¹,

Wang²,

Song³

et al. 2020

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Despite the marked progress in recent years, structured light-based three-dimensional (3D) measurement techniques still have difficulty in capturing mirror surface reflection. The accuracy of 3D reconstruction for mirror objects should be further improved to adapt to the high reflectivity and curvature of such objects. To improve the stripe definition and reconstruction accuracy of highly reflective mirror objects, this paper analyzes the local blur of defocus stripes in phase measuring deflectometry (PMD) system, and presents a method to analyze the spatially varying defocusing and de-blurring, with the aid of a 3D block matching algorithm, thereby focusing on defocus stripes. Experimental results show that the proposed method can achieve micron-level reconstruction accuracy of standard flat mirrors, and detect the defects on highly reflective mirror objects at a high precision.

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Section: Analysis Of Wrapped Phase and Dephasing Algorithmmentioning

confidence: 99%

Three-Dimensional Mirror Surface Measurement Based on Local Blur Analysis of Phase Measuring Deflectometry System

Sun¹,

Wang²,

Song³

et al. 2020

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“…where ∆ φ r and ∆ φ are the errors of φ r and φ, respectively. These phase errors may derive from sensor noise [6,25], gamma distortion [26], or projector/camera defocus [27]. Sensor noise is not typically the main factor that influences phase unwrapping errors unless scanning at very low SNRs.…”

Section: Optimal Reference Frequency Selectionmentioning

confidence: 99%

Automatic look-up table based real-time phase unwrapping for phase measuring profilometry and optimal reference frequency selection

Song¹,

Lau²,

Ho³

et al. 2019

Opt. Express

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For temporal phase unwrapping in phase measuring profilometry, it has recently been reported that two phases with co-prime frequencies can be absolutely unwrapped using a look-up table; however, frequency selection and table construction has been performed manually without optimization. In this paper, a universal phase unwrapping method is proposed to unwrap phase flexibly and automatically by using geometric analysis, and thus we can programmatically build a one-dimensional or two-dimensional look-up table for arbitrary two co-prime frequencies to correctly unwrap phases in real time. Moreover, a phase error model related to the defocus effect is derived to figure out an optimal reference frequency co-prime to the principal frequency. Experimental results verify the correctness and computational efficiency of the proposed method.

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“…The accuracy is influenced by many factors. The defocus of projector influences the fringe patterns' amplitude and decreases the signal-to-noise ratio [2], which can be improved by increasing the phase-shifting steps [3] or selecting the fringe frequency properly [4]. The gamma effect of projector causes the fringe images to be nonsinusoidal waveforms and leads to phase error.…”

Section: Introductionmentioning

confidence: 99%

Accuracy analysis of fringe projection profilometry using raytracing algorithm and BP neural network

Zhao

Liu

Jiang

et al. 2023

International Conference on Optical and Photonic Engineering (icOPEN 2022)

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Fringe projection profilometry is widely used in manufacturing and the accuracy analysis is the key to promote this technology in engineering applications. Researches analyze influencing factors including gamma effect, intensity noise, defocus and methods are proposed to improve the measurement accuracy. However, an analytical study is difficult to perform and the surface shape of the measuring objects influence the fringe images which needs to be considered. In this paper, raytracing algorithm and back-propagation network are used to study the relationship between the surface shape and measurement accuracy. The fringe projection profilometry system is simulated in computer using the raytracing algorithm and the light transport coefficients are measured to improve the accuracy of the camera defocus simulation. The impact of surface shape on fringe images is analyzed, and the projection and observation angles are used as the input of the network. The truth value of the surface is known in the simulation model thus the error of the coordinate can be obtained after simulation measurement and used as the output of the network. Experiment show that, high correlation exists between the surface shape and the coordinate error.

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Local blur analysis and phase error correction method for fringe projection profilometry systems

Cited by 31 publications

References 17 publications

Three-Dimensional Mirror Surface Measurement Based on Local Blur Analysis of Phase Measuring Deflectometry System

Three-Dimensional Mirror Surface Measurement Based on Local Blur Analysis of Phase Measuring Deflectometry System

Automatic look-up table based real-time phase unwrapping for phase measuring profilometry and optimal reference frequency selection

Accuracy analysis of fringe projection profilometry using raytracing algorithm and BP neural network

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