• Title/Summary/Keyword: moire

Search Result 280, Processing Time 0.032 seconds

A Study on the Phase Measuring Profilometry with Parallel-optical-axes (평행 광축에서의 위상측정 형상측정법에 관한 연구)

  • 정경민;박윤창;박경근
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.6
    • /
    • pp.210-217
    • /
    • 2000
  • Noncontact measuring methodology of 3-dimensional profile using CCD camera are very attractive because of it's high measuring speed and it's high sensitivity. Especially when projecting a grid pattern over the object, the captured image have 3 dimensional information of the object. Projection moire extract 3-D information with another grid pattern in front of CCD camera. However phase measuring profilometry(PMP) obtain similar results without additional grid pattern. In this paper, the projection moire are compared with the PMP mathematically, and it is shown that PMP can generate moire image with simple mathematical computations. Experimental works are also carried out showing the same results. It is shown that using a single gird pattern, moire image can be obtained directly without any mathematical operation when some conditions are satisfied.

  • PDF

Study on Bulge Test by Moire Method (모아레法 에 의한 벌지試驗 에 관한 硏究)

  • 백남주;지용주;강대민
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.7 no.3
    • /
    • pp.286-293
    • /
    • 1983
  • This study measures polar compressive thickness strain and radius of curvature of the bulge through Moire' method in bulge test. Hill's and Alexander's bulge theories, instability conditions derived by Swift's, Hill's, Alexander's and wang's theories, are also investigated, compared with Moire' experimental results. In order to review and compare with Hill's and Alexander's bulge theories, the relationships between radius of curvature of the bulge and polar height, between polar compressive thickness strain and polar height, are used. Mild steel, soft copper and commercial pure aluminum are used in Moire' experiment. According to this study, Hill's and Alexander's bulge theories, instability conditions derived by Swift's, Hill's, Alexander's and Wang's theories are agreement to Moire' experiment results.

A study on 3-D shape measurement for the composition of human bust (인체흉상 합성을 위한 3차원 형상 측정에 관한 연구)

  • 안중근;강영준;최정표;유원재
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1997.10a
    • /
    • pp.220-223
    • /
    • 1997
  • Moire topography method is a well-known non-contacting 3-D measuement method. Recently, the automatic 3-D measurement by moire topography has been required since the method was frequently applied to the engineering and medical fields. 3-D measurement using projection moire topography is very attractive because of it's high measuring speed and high sensitivity. In this paper, using two-wavelength method of projection moire topography tested to measuring object with the 2x-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the 2x-ambiguity problem can be effectively overcome so as to treat large step discontinuities in measured objects.

  • PDF

A Study on the Improvement of Accuracy of Surface Measurement in the Phase-Shifting Shadow Moir$\'{e}$ Method (위상이동 그림자 무아레방법을 이용한 형상측정법의 정확도 개선에 관한 연구)

  • 강영준;유원재;권용기
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.15 no.10
    • /
    • pp.96-102
    • /
    • 1998
  • In this study, the theory and application of phase-shifting shadow moire topography is focused on the non-contact measurement of object surfaces for practical use in the field of production engineering. Shadow moire topography has been studied during last few decades in the area of the optical physics, and now its mathmatical theory has been established. Generally, in case of the classical shadow moire topography, the sensitivity is a few tenths of millimeter in best cases. Here we tried the application of phase-shifting method to the conventional shadow moire topography. But the reference grating and the deformed grating are mutually dependent because it is impossible to obtain uniform phase shifts on the whole Held. Therefore it is difficult to use a phase-shifting method in shadow moire topography. However, it was shown that constant phase-shifting was able to be measured by moving both the grating and light source. Finally we obtained a better result by using this procedure and applied the phase-shifting shadow moire to three dimensional object measurement.

  • PDF

A Study on Mapping using Projection Moir Technique (투영 모아레 기법을 이용한 Mapping에 관한 연구)

  • 유복모;이성옥;유광호
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.3 no.2
    • /
    • pp.1-10
    • /
    • 1985
  • Moire technique is generally divided into shadow Moire Technique and Projection Moire Technique. In this paper, determinating the direction of reference planes for this system, by comparing the results of this system with those of general terrestrial photogrammetry, is an objective of this paper. For the objective, control surveying is done and the results of control surveying are compared with those of moire photograph. In this technique, it is found that though the positions of a projector and a reference grid are not moved, a desired moire contour whose the reference plane is different respectively is easily obtained by changing the pitches of a master grid and a reference grid on an object. Also it is found that when the pitches of the two grids on an object are equal, a moire contour which has the reference plane parallel to the object can be obtained.

  • PDF

Visual Measurement of Rotational Displacements by Using Two Different Moire Fringes Simultaneously Generated by Repeated Sinusoidal Gratings (반복사인격자에서 동시에 생기는 두 가지 무아레 무늬를 이용한 회전변위의 가시적 측정)

  • Jeong, Youn-Hong;Oh, Jeong-Hyo;Jo, Jae-Heung
    • Korean Journal of Optics and Photonics
    • /
    • v.19 no.4
    • /
    • pp.302-309
    • /
    • 2008
  • We present the precise visual measurement method of rotational displacements using two different moire fringes simultaneously generated by repeated sinusoidal gratings. We investigate the variation of moire fringes depending on rotational displacements through computer simulation and experiment using a rotator in detail. The moire fringes are composed of the wide linear fringe part with a long period and the narrow linear fringe part with a short period. These parts are superior to the angle detection of more than 12 degrees and less than 12 degree, respectively. Additionally, the method can be visually used in the determination of the rotational direction by observing the moire fringe's direction.

A Morphological Study On The Upper Face Of Moire According To The Sasang Constitution (사상체질별(四象體質別) 상안부(上顔部) Moire 형태(形態)의 특징(特徵)에 관한 연구(硏究))

  • Hong, Suck-chull;Lee, Eui-ju;Lee, Su-kyung;Han, Gi-hwan;Kho, Byung-hee;Song, Il-byung
    • Journal of Sasang Constitutional Medicine
    • /
    • v.10 no.2
    • /
    • pp.271-281
    • /
    • 1998
  • 1. Objective : This research is a study about constitutional diagnosis through the external appearances, especialy it is for finding shape differences of the upper-face pictures of moire, according to the Sasang constitution 2. Method : We have collected 98 cases of femail patients of the Sasang Constitutional Department, including employees of the Kyung-Hee Medical Center and took pictures of moire of upper face and measured 50 points. We analyzed shape differences of the upper face according to the Sasang constitution. 3. Results : Analysing the moire of upper face, the characteristics according to sasang constitution presented. 4. Conclusion : Soyangin had a projected part of left upper face compared with taeumin. With the image of moire, the characteristics of upper face according to sasang constitution was found.

  • PDF

Vibration Analysis and Design of CRT for Reduction of Moire Phenomena (CRT 모아레 현상의 억제를 위한 진동 해석 및 설계)

  • 이규헌;유홍희
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2001.11a
    • /
    • pp.413-418
    • /
    • 2001
  • The moire phenomena, which are induced by mask vibration due to the excitation of speakers, degrades the color purity of CRT. So it is important to eliminate this phenomena to obtain a good CRT design. In this study we analyze the mask vibration by experiment as well as finite element method. To obtain the finite element solutions efficiently, an equivalent model was employed. The experimental and analysis results show reasonable agreements. An enhanced design configuration of mask welding points are suggested through this study.

  • PDF

Automatic Generation of 3D Models using ETRI- Moire Scanner (ETRI-모아레 스캐너를 이용한 3차원 모델의 자동생성)

  • 권대현;최이배;이의택
    • Proceedings of the Korean Society of Broadcast Engineers Conference
    • /
    • 1999.11b
    • /
    • pp.47-52
    • /
    • 1999
  • The visualization of Moire or laser-scanned data has been explored by many researchers and has been an important issue on computer graphics research. In this paper, we present various techniques that handle tremendous amount of 3D range data which are generated by the ETRI- Moire Scanner. The techniques include constructing an efficient data structure, constructing triangle meshes and decimation and registration of multiple-view range images and textures.

  • PDF

Effect of Base Paper and Binder on the Printability of Coated Paper (코팅원지 및 바인더가 코팅지의 인쇄적성에 미치는 영향)

  • 이용규
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.15 no.2
    • /
    • pp.57-76
    • /
    • 1997
  • A color halftoning is the process of generating halftone images for the different color plans, for example, cyan, magenta, yellow, and black for a offset printing device. A conventional halftone technique, so called AM screening, is simple and easy to implement, but the halftoned dot patterns by using this method is not free for the moire` fringe. Moire` patterns are caused the power spectrum distribution on low spatial frequency domain. To avoid Moire` patterns, the conventional screen require the different screen angles for each color plans. Recently, Ultra-fine and 7 color printing methods are developed to expend the color gamut. In 7 color printing method must be used the halftone technique of random and blue noise characteristic to avoid Moire` fringe.

  • PDF