Quantitative evaluation of powder spray effects on stereovision measurements

Huang, Zhenhua; Ni, Jun; Shih, Albert J.

doi:10.1088/0957-0233/19/2/025502

Cited by 8 publications

(3 citation statements)

References 21 publications

(22 reference statements)

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“…In optical metrology it is common practice to prepare optically challenging surface with a spray [12]. This makes the surface optically diffuse while preserving the geometry.…”

Section: Methodsmentioning

confidence: 99%

An Error Analysis of Structured Light Scanning of Biological Tissue

2017

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Abstract. This paper presents an error analysis and correction model for four structured light methods applied to three common types of biological tissue; skin, fat and muscle. Despite its many advantages, structured light is based on the assumption of direct reflection at the object surface only. This assumption is violated by most biological material e.g. human skin, which exhibits subsurface light reflection. In this study, we find that in general, structured light scans of biological tissue deviate significantly from the ground truth. We show that a large portion of this error can be predicted with a simple, stochastic linear model based on the scan geometry. As such, scans can be corrected without introducing any specially designed pattern strategy or hardware. We can effectively reduce the error in a structured light scanner applied to biological tissue by as much as factor of two or three.

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“…In optical metrology it is common practice to prepare optically challenging surface with a spray [12]. This makes the surface optically diffuse while preserving the geometry.…”

Section: Methodsmentioning

confidence: 99%

An Error Analysis of Structured Light Scanning of Biological Tissue

2017

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“…In practice, the prevailing solution is surface coating of micro-white powders, which can make the surface exhibit uniform Lambertian reflection, but due to the thickness of powders, it is not recommended in 3D inspection applications [10]. In particular, the quality of fringe images is the net effect of camera exposure time, camera sensor gain, lens aperture, intensity of projected light, reflectivity and shape of measured surfaces, environment light, shading and occasions, etc., so in order to improve the quality of fringe image of surfaces with large reflectivity variation range, many research works tried to control some of these factors [11][12][13][14][15][16][17][18][19][20].…”

Section: Oet Calibration Methodsmentioning

confidence: 99%

Enhanced phase measurement profilometry for industrial 3D inspection automation

Zhong

Zhou

et al. 2014

Int J Adv Manuf Technol

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Industrial metrology and inspection systems commonly rely on phase measurement profilometry (PMP) using sinusoidal fringe patterns projecting, yielding dense, and accurate 3D reconstruction regardless of the presence of texture. However, applying PMP method to industrial 3D inspection is still a big challenging problem due to rigorous industrial measurement conditions including large surface reflectivity variation range and vibration. Aiming to solve these problems, an enhanced phase measurement profilometry (EPMP) is proposed. In EPMP, an optimal exposure time (OET) calibration method is proposed to solve large surface reflectivity variation range problem, and it can avoid saturating the camera sensor in areas of specular reflection while keep the signalto-noise ratio (SNR) of fringe image in areas of weak reflection at most. To resist the influence of vibration, an improved pose calibration method (IPC) is used to allow fast calibration of pose of cameras by acquiring only one image of planar target. Moreover, an automatic online 3D inspection system for evaluating 3D geometric dimension quality of railway truck adapter (RTA) is developed, and according to the experiments, the EPMP indicates a satisfactory result in accuracy and repeatability, which can meet the requirements of the 3D inspection task in industrial measurement conditions.

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“…In order to facilitate such measurements the surfaces are often sprayed with powder to suppress the reflections, and at the 50 mm level of uncertainty such spray material can influence the measurement results. This problem has been investigated by Huang et al [66] who conclude that improved optical techniques are needed that can take account of the problems associated with specular reflection.…”

Section: Three-dimensional Systems: Structured Lightmentioning

confidence: 99%

Recent developments in large-scale dimensional metrology

Peggs

Maropoulos

Hughes

et al. 2009

Proceedings of the Institution of Mechanical Engineers, Part B:

172

117

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With ever-more demanding requirements for the accurate manufacture of large components, dimensional measuring techniques are becoming progressively more sophisticated. This review describes some of the more recently developed techniques and the state-of-the-art in the more well-known large-scale dimensional metrology methods. In some cases, the techniques are described in detail, or, where relevant specialist review papers exist, these are cited as further reading. The traceability of the measurement data collected is discussed with reference to new international standards that are emerging. In some cases, hybrid measurement techniques are finding specialized applications and these are referred to where appropriate.

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Quantitative evaluation of powder spray effects on stereovision measurements

Cited by 8 publications

References 21 publications

An Error Analysis of Structured Light Scanning of Biological Tissue

An Error Analysis of Structured Light Scanning of Biological Tissue

Enhanced phase measurement profilometry for industrial 3D inspection automation

Recent developments in large-scale dimensional metrology

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