Single shot laser speckle based 3D acquisition system for medical applications

Khan, Danish,Shirazi, Muhammad Ayaz,Kim, Min Young Elsevier 2018 Optics and lasers in engineering Vol.105 No.-

<P><B>Abstract</B></P> <P>The state of the art techniques used by medical practitioners to extract the three-dimensional (3D) geometry of different body parts requires a series of images/frames such as laser line profiling or structured light scanning. Movement of the patients during scanning process often leads to inaccurate measurements due to sequential image acquisition. Single shot structured techniques are robust to motion but the prevalent challenges in single shot structured light methods are the low density and algorithm complexity. In this research, a single shot 3D measurement system is presented that extracts the 3D point cloud of human skin by projecting a laser speckle pattern using a single pair of images captured by two synchronized cameras. In contrast to conventional laser speckle 3D measurement systems that realize stereo correspondence by digital correlation of projected speckle patterns, the proposed system employs KLT tracking method to locate the corresponding points. The 3D point cloud contains no outliers and sufficient quality of 3D reconstruction is achieved. The 3D shape acquisition of human body parts validates the potential application of the proposed system in the medical industry.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A single shot 3D acquisition system based on stereophotogrammetry and laser speckle projection is presented for anthropometric measurements. </LI> <LI> The stereo correspondence is established by tracking the feature points using KLT feature tracker instead of laser speckle correlation. </LI> <LI> The acquisition of the 3D point clouds by the proposed system contains no outliers and the number of 3D points is sufficient to create the 3D mesh of the measuring part. </LI> <LI> Experiments are performed to estimate the measurement accuracy of the system. </LI> </UL> </P>

3D 스캔 시 품질향상을 위한 스프레이 도포 자동화 장비 개발

김원섭(Kim, Wonseop),조재흥(Jo, Jae Heung),김동수(Kim, Dong-Su),김동규(Kim Dong-Gyu),홍석무(Hong, Seokmoo) 한국산학기술학회 2016 한국산학기술학회논문지 Vol.17 No.4

3D 프린터의 증가에 따라 대량 생산이 아닌 소량 제품의 빠른 개발 시간을 고려하여 3D 스캐너의 활용도 점차 증가하고 있다. 소량 생산 개발 트렌드뿐만 아니라 최근 자동차 및 전자부품의 제조업에 있어서도 정밀 부품의 개발 및 검사, 측정 등의 품질 문제가 중요한 이슈로 떠오르고 있다. 최근 3D 스캐너 장비 효율성 및 인식기술은 지속적으로 향상되었지만, 이에 반해, 이를 준비하는 스프레이 작업은 시간이 많이 걸리고 환경문제가 유발되기 때문에 제조업 제품 개발자들은 자동스 프레이 도포 시스템 개발에 대해 지속적으로 요구해 왔다. 본 연구를 통해서 3D 스캔 준비 작업으로 필요한 스프레이 자동 도포 장비를 개발하였으며, 스프레이 도포 시 균일하게 미세 분말이 도포 될 수 있도록 파라미터 세팅에 대해 실험적으로 연구하였다. 결과적으로 빠르고 쉬운 자동 스프레이 도포 장비가 개발 되었고, 이를 활용해서 3D 측정을 위한 준비 시간이 기존 대비 1/10수준으로 단축되었다. 또한 다양한 조건에 대한 비교를 통해 최적의 도포 조건을 실험적으로 제시하였다. The use of 3D scanners has increased gradually according to increasing 3D printer applications. The precision inspection of car parts or electronic components is an important issue not only in the field of mass production, but also in small-scale production. Recently, 3D scanner equipment efficiency and recognition technology has been improved continuously. On the other hand, the spraying time to prepare 3D scanning is time-consuming and has environmental problems. Therefore, an automatic spray system has been in demand by the manufacturing industry. Automatic spray equipment was newly developed for the preparation of a 3D scanner. In this research, the automatic spray system guarantees uniform spray operation. To determine the optimal spray parameters, various spraying methods, solutions and conditions were tested and compared with the experiments. The preparation time for 3D scanning was reduced to 1/10 compared to the manual spraying time, and indicates the optimal spraying conditions through a comparison of various spray coating conditions.

3차원 광학 측정을 위한 디지털 프린지 투사에 있어서 LCD 비선형 감마 에러 개선 방법

김우성 한국광학회 2020 한국광학회지 Vol.31 No.3

Optical three-dimensional (3D) measurement systems based on digital fringe projection are used in many contactless measurement applications. The system which can measure a dozen micrometers uses a liquid-crystal display (LCD) as the projection unit for generating a digital fringe pattern, because a flexible fringe pattern can be easily made by computer software. According to the gamma nonlinearity of the LCD projection unit, the digital fringe projection error on the object affects the accuracy of 3D object measurement. An improved method of LCD gamma-nonlinearity error reduction is proposed, by using the inverse function of the intensity transfer function to improve the accuracy. The improvement due to the proposed method is shown by measuring the difference in precision between a computer-generated sine wave and a camera-obtained sine wave for a standard semiconductor specimen.

3차원 광학 측정을 위한 디지털 프린지 패턴 영상에 있어서 비균일성 광원 투사 효과에 관한 연구

김우성 水原大學校 2020 論文集 Vol.34 No.-

A digital fringe projection is used in a lot of contactless measurement applications for The optical 3D measurement system. The system which can measure a dozen of μm uses LCD with light source as a projection unit for generating digital fringe pattern because a flexible fringe pattern can be easily made by computer software. According to non uniform projection of light source, the amplitude of digital fringe projection on the object affects the accuracy of 3D object measurement. The effect of light source non-uniformity is analyzed and showed by using the standard deviation which is a noise measurement factor in a digital fringe projection image. The image is measured by the optical 3D measurement system with a standard semiconductor specimen. The improved method for the reduction of the effect caused by non-uniformity light source is also proposed.

스테레오 비전과 포토메트릭 스테레오를 혼합한 광학식 3 차원 측정기술

최태환(Taehwan.Choi),변성호(Seongho.Byeon),장민호(Minho.Chang) (사)한국CDE학회 2013 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2013 No.1

고정밀 3차원 측정을 위한 다중 줄무늬 투영 방법에 관한 연구

장민호(Minho Chang) Korean Society for Precision Engineering 2007 한국정밀공학회지 Vol.24 No.2

This paper proposes a novel method of projecting a multiple stripe pattern whose intensity profile is sinusoidal. The sinusoidal stripe patterns are plated with chromium on a piece of glass, and the glass is placed within an optical projection system. By linearly moving the glass along the direction of the stripe pattern, the projection system generates the motion blurring effect, and as a result, produces a blurred stripe pattern whose intensity profile is sinusoidal along the perpendicular direction of the stripe pattern. The sinusoidal pattern improves the measurement accuracy of phase- . shifting method. Experimental results are provided for three different types of stripe patterns: rectangle, diamond, and sinusoid.

3차원 고해상도 정밀 표면 측정의 기술과 응용

현재상(Jae-Sang Hyun) 한국트라이볼로지학회 2023 한국트라이볼로지학회 학술대회 Vol.2023 No.10

Recent Trends on a Precision Dimensional Sensor Using Optical Modulation Techniques

장윤수(Yoon-Soo Jang),박정재(Jungjae Park),진종한(Jonghan Jin) Korean Society for Precision Engineering 2021 한국정밀공학회지 Vol.38 No.12

Optical dimensional metrology has playing a long-term key role from high-precision engineering to large-scale industrial manufacturing. Various methods of optical dimensional metrology have been proposed and demonstrated to respond to the ever-growing industrial demands as well as fundamental science demands for the measurement precision and range. However, most of them demonstrated under laboratory conditions have a long way to go outside the laboratory. Here, we present a progress review on optical modulation technique-based dimensional metrology, which has already been used in real applications and has been commercialized. Amplitude modulation (AM) and frequency modulation (FM) based dimensional measurement techniques are described with their operating principles, and recent progresses and applications in 3D imaging are presented in this review.

인체측정용 3차원 스캐너 제작

김민효,남윤자,Kim, Min-Hyo,Nam, Yun-Ja 대한인간공학회 2001 大韓人間工學會誌 Vol.20 No.3

A three dimensional body scanner for anthropomentric measurement has been developed. In this study, the slit laser beam projection method followed by digital image processing was used to provide accurate spatial data with the typical optical triangulation method to overcome the many difficulties in traditional in accurate and time-consuming tactic measurement method using rulers and gauges. Compared with other commercialized scanners. this system can obtain a relatively wide range of data at a much lower cost by the specially designed scanning process such as the simultaneous acquisition of vertical and horizontal body cross-section profiles.

거친 가공표면 형상 측정법

권용관(Yong-Kwan Kwon),김세헌(Se-Heon Kim),김병창(Byoung-Chang Kim),김원일(Won-Il Kim) 한국기계가공학회 2006 한국기계가공학회 춘추계학술대회 논문집 Vol.2006 No.-

We present a method of 3-D profile measurement to obtain the xyz-coordinates of roughly processed surface which has the light scatted characteristics on the optical point of view. The proposed device comprises multiple two-point-diffraction sources made of a pair of single-mode optical fibers, and performs a profile measurement by projecting multiple fringe patterns on the surface under test. The measurement results proved that the proposed method is well suited for the roughly processed surfaces.