Fabrication of digital sinusoidal gratings and precisely controlled diffusive flats and their application to highly accurate projected fringe profilometry

Su, Wei‐Hung; Liu, Hongyu; Reichard, Karl; Yin, Shizhuo; Yu, Francis T. S.

doi:10.1117/1.1573217

Cited by 29 publications

(22 citation statements)

References 9 publications

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“…Based on the theory of reference [17], the meaning of Eq. (7) is that the intensity of sinusoidal curve can be presented by performing integral of area.…”

Section: The Theory Of Improved Ellipse Binary Patternmentioning

confidence: 99%

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Three-dimensional measurement of object surface by using ellipse binary defocusing projection

2017

J. Eur. Opt. Soc.-Rapid Publ.

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Background: The accuracy of three-dimensional measurement of object surface is always affected by the nonlinear gamma of the projector. The defocusing binary projection can overcome the nonlinear gamma distortion of the projector and reduce the effect of high harmonics without gamma calibration. Although researches have already reduced the errors to get a clear sinusoidal curve, there still leave room for improvement, especially when wide stripes are applied during the measurement. Methods: This paper presents a kind of ellipse binary pattern. By analyzing the property and spectrum, the binary pattern can produce high quality sinusoidal curve and produce smaller errors. It has a better effect to use an ellipse pattern to overcome the nonlinear gamma distortion of the projector and it is suit to be used as wide stripes. Results: Simulation and comparison experiments plus three-step phase shifted method are conducted to verify feasibility and accuracy of this binary pattern. The experimental results have indicated that this binary pattern can increase the accuracy of 3D measurement and reduce phase errors caused by the nonlinear gamma of the projector. The defocusing ellipse pattern is superior to traditional methods. In addition, the defocusing binary stripe is robust and suit to measure object with large period.

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“…Based on the theory of reference [17], the meaning of Eq. (7) is that the intensity of sinusoidal curve can be presented by performing integral of area.…”

Section: The Theory Of Improved Ellipse Binary Patternmentioning

confidence: 99%

“…But this pattern should be combined into at least eight RGB color images. Su [17] uses the area method to generate wide stripes. The advantage of this method can get high quality sinusoidal, but the process is time-costing.…”

Section: Introductionmentioning

confidence: 99%

Three-dimensional measurement of object surface by using ellipse binary defocusing projection

2017

J. Eur. Opt. Soc.-Rapid Publ.

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“…A pictorial representation of the same with more details is shown in Fig. 3.During the last three decades, fringe projection techniques have developed tremendously due to the contribution of large number of researchers and the developments can be broadly categorized as follows: design or structure of the pattern used for projection [40,41,42,43,44,45,46,47,48,49], method of generating and projecting the patterns [50,51,52,53,54,55,56,57,58,59,60,61,62], study of errors caused by the equipment used and proposing possible corrections [63,64,65,66], developing new fringe analysis methods to extract underlying phase distribution …”

mentioning

confidence: 99%

“…Fiber optic interferometer system with the laser diode input enables one to have greater flexibility and compactness of the measurement system [52]. Grating projection systems [53,54], spatial light modulators [55], diffractive optical elements [56], superluminiscent diode in conjunction with an acousto-optic tunable filter [57], programmable LCDs [45], multi-core optical fibers [58,59] etc. are among the other methods that are in practice used to generate and project structured patterns onto the objects.…”

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confidence: 99%

Fringe projection techniques: Whither we are?

Gorthi

Rastogi

2010

Optics and Lasers in Engineering

1,151

376

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During recent years, the use of fringe projection techniques for generating three-dimensional (3D) surface information has become one of the most active research areas in optical metrology. Its applications range from measuring the 3D shape of MEMS components to the measurement of flatness of large panels (2.5 m × .45 m). The technique has found various applications in diverse fields: biomedical applications such as 3D intra-oral dental measurements [1], non-invasive 3D imaging and monitoring of vascular wall deformations [2], human body shape measurement for shape guided radiotherapy treatment [3,4], lower back deformation measurement [5], detection and monitoring of scoliosis [6], inspection of wounds [7,8] and skin topography measurement for use in cosmetology [9,10, 11]; industrial and scientific applications such as characterization of MEMS components [12,13], vibration analysis [14,15], refractometry [16], global measurement of free surface deformations [17,18], local wall thickness measurement of forced sheet metals [19], corrosion analysis [20,21], measurement of surface roughness [22,23], reverse engineering [24,25,26], quality control of printed circuit board manufacturing [27,28,29] and heat-flow visualization [30]; kinematics applications such as measuring the shape and position of a moving object/creature [31,32] and the study of kinematical parameters of dragonfly in free flight [33,34]; biometric identification applications such as 3D face reconstruction for the development of robust face recognition systems [35,36]; cultural heritage and preservation [37,38,39] etc.One of the outstanding features of some of the fringe projection techniques is their ability to provide high-resolution, whole-field 3D reconstruction of objects in a non-contact manner at video frame rates. This feature has backed the technique to pervade new areas of applications such as security systems, gaming and virtual reality. To gain insights into the series of contributions that have helped in unfolding the technique to acquire this feature, the reader is referred to the review articles in this special issue by Song Zhang, and Xianyu Su et al.A typical fringe projection profilometry system is shown in Fig 1. It consists of a projection unit, an image acquisition unit and a processing/analysis unit. Measurement of shape through fringe projection techniques involves (1) projecting a structured pattern (usually a sinusoidal fringe pattern) onto the object surface, (2) recording the image of the fringe pattern that is phase modulated by the object height distribution, (3) calculating the phase modulation by analyzing the image with one of the fringe analysis techniques (such as Fourier transform Figure 1: Fringe projection profilometry system method, phase stepping and spatial phase detection methodsmost of them generate wrapped phase distribution) (4) using a suitable phase unwrapping algorithm to get continuous phase distribution which is proportional to the object height variations, and finally (5) calibrating the system for m...

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“…Some recent work has also been performed utilising specialised projection sources projecting highly controlled grating patterns. Such specialised projection sources are capable of achieving very high accuracies down to the micron level, however, such solutions are quite expensive [14]. This work is primarily concerned with more typical projection sources namely DFP by way of video projection but is general enough to analyse any digital projection scheme.…”

Section: A Review Of Dfp Fringe Profilometrymentioning

confidence: 99%

Accuracy Limitations Introduced by Digital Projection Sources in Profilometric Optical Metrology Systems

Baker

Chicharo

et al.

Conference on Optoelectronic and Microelectronic Materials and Devices, 2004.

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The accuracy of profilometric optical metrology systems utilising Digital Fringe Projection (DFP) is analysed. An analytical model to describe theoretical accuracy limitation is derived and given as a function of object distance from the projector, projector resolution, projection angle and also object gradient. Associated limitations of the model are also discussed and analysed. The validity of the new model is demonstrated through practical experimentation. Disciplines Physical Sciences and Mathematics Publication DetailsThis article

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Fabrication of digital sinusoidal gratings and precisely controlled diffusive flats and their application to highly accurate projected fringe profilometry

Cited by 29 publications

References 9 publications

Three-dimensional measurement of object surface by using ellipse binary defocusing projection

Three-dimensional measurement of object surface by using ellipse binary defocusing projection

Fringe projection techniques: Whither we are?

Accuracy Limitations Introduced by Digital Projection Sources in Profilometric Optical Metrology Systems

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