• Title/Summary/Keyword: projection Method

Search Result 1,547, Processing Time 0.03 seconds

Curved MPR System Disease by Using HU Values (HU값을 이용한 질환 별 Curved MPR 시스템)

  • Song, Jong-Nam;Kim, Eung-Kon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2010.10a
    • /
    • pp.349-351
    • /
    • 2010
  • Recently, we were able to get thinner projection supplied by multi detector CT. Not only 'axial projection' is used to decode the examination but asks resctructured projections in various directions. MPR technique is capable of drawing flexible curves to produce projection reenactment which enables describing details of a part that is desired but it has a disadvantage that curvy blood vessels like 'willis circle artery' distorting. This essay suggested Curved MPR method based on different disorders which was improved using distinction of HU value along with existing MPR method. After reconstructing the projection using the suggested method, the projection was transmitted by using PACS and it confirmed its usefulness of decoder's efficiency diagnosis.

  • PDF

Recognition of English Calling Cards by Using Projection Method and Enhanced RBE Network

  • Kim, Kwang-Baek
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.13 no.4
    • /
    • pp.474-479
    • /
    • 2003
  • In this paper, we proposed the novel method for the recognition of English calling cards by using the projection method and the enhanced RBF (Radial Basis Function) network. The recognition of calling cards consists of the extraction phase of character areas and the recognition phase of extracted characters. In the extraction phase, first of all, noises are removed from the images of calling cards, and the feature areas including character strings are separated from the calling card images by using the horizontal smearing method and the 8-directional contour tracking method. And using the image projection method, the feature areas are split into the areas of individual characters. We also proposed the enhanced RBF network that organizes the middle layer effectively by using the enhanced ART1 neural network adjusting the vigilance threshold dynamically according to the homogeneity between patterns. In the recognition phase, the proposed neural network is applied to recognize individual characters. Our experiment result showed that the proposed recognition algorithm has higher success rate of recognition and faster learning time than the existing neural network based recognition.

A method for image-based shadow interaction with virtual objects

  • Ha, Hyunwoo;Ko, Kwanghee
    • Journal of Computational Design and Engineering
    • /
    • v.2 no.1
    • /
    • pp.26-37
    • /
    • 2015
  • A lot of researchers have been investigating interactive portable projection systems such as a mini-projector. In addition, in exhibition halls and museums, there is a trend toward using interactive projection systems to make viewing more exciting and impressive. They can also be applied in the field of art, for example, in creating shadow plays. The key idea of the interactive portable projection systems is to recognize the user's gesture in real-time. In this paper, a vision-based shadow gesture recognition method is proposed for interactive projection systems. The gesture recognition method is based on the screen image obtained by a single web camera. The method separates only the shadow area by combining the binary image with an input image using a learning algorithm that isolates the background from the input image. The region of interest is recognized with labeling the shadow of separated regions, and then hand shadows are isolated using the defect, convex hull, and moment of each region. To distinguish hand gestures, Hu's invariant moment method is used. An optical flow algorithm is used for tracking the fingertip. Using this method, a few interactive applications are developed, which are presented in this paper.

A Study on the Calibration of Shape Measurement System Using Digital moire (Digital moire 형상측정 시스템의 보정에 관한 연구)

  • 유원재;김도훈;안재웅;강영준;노형민
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2002.05a
    • /
    • pp.199-202
    • /
    • 2002
  • Moire topography method is a well-known non-contacting 3-D measurement 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 digital projection moire topography is very attractive because of its high measuring speed and high sensitivity. In this paper, using different N-bucket algorithm method of digital projection moire topography is tested to measuring object with the 2$\pi$-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding measurement errors that decreased more by using the flour-three step algorithm method than the same step in the phase shifting of different pitchs.

  • PDF

The Analysis of Creep characteristics for Turbine blade using Theta projection method (θ 투영법을 이용한 터빈 블레이드의 크리프 특성 분석)

  • Lee, Mu-Hyoung;Han, Won-Jae;Jang, Byung-Wook;Lee, Bok-Won;Park, Jung-Sun
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.39 no.4
    • /
    • pp.321-331
    • /
    • 2011
  • The present work is aimed to analyze the creep characteristics of a turbojet engine turbine blade using the theta projection method. The theta projection method has been widely used due to its advantages and flexibility. For the creep characteristic analysis of the turbine blade, tests are performed considering the operating conditions and the non-linear material properties. Results from the creep test are fitted using the four theta model. The predicted proprieties using the four theta model are compared with the prediction model and creep test results. To obtain an optimum value of the four theta parameters in non-linear square method, a number of computing processes in the non-linear least square method were carried out to obtain full creep curves. Results using the theta model has more than 0.95 value of $R^2$. The results between the experimental values and predicted four theta model has about 90.0% accuracy. The theta projection method can be utilized for a design purpose to predict the creep behavior.

A Study on the Comparision Between Map Projection Methods of TM and Polyhedric (TM 및 다면체 투영법(投影法)의 비교고찰(比較考察))

  • Park, Wei-Keun
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.6 no.2 s.12
    • /
    • pp.119-132
    • /
    • 1998
  • Much information on the terrain and the space has been depicted to maps of various form according to the map scale and the application. In Korea the base map system was made by only one projection method(Transvers Mercator projection). This is the reason to study this paper, because I think singular map projection method can't satisfy the various map scales and application. In this paper Meridian Are Length, Parallel Are Length of ellipsoid and the area of ellipsoidal surface-the length, the width and area of the map scale 1/5,000, 1/25,000, 1/5,000, 1/1,000, will be calculated and transformed to the plane length and area by Transvers Mercartor projection and Polyhedrical projection. The projection distortion which came into existence on this occasion was compared and analyzed by this Paper. And Properties on TM and Polyhedrical projection were understood. Lastly this paper intended to present suitable map projections according to the map scales and the purpose of use.

  • PDF

Foreground object detection in projection display (프로젝션 화면에서 전경물체 검출)

  • Kang Hyun;Lee Chang Woo;Park Min Ho;Jung Keechul
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.41 no.1
    • /
    • pp.27-37
    • /
    • 2004
  • The detection of foreground objects in a projection display using color information can be hard due to changing lighting conditions and complex backgrounds. Accordingly, the current paper proposes a foreground object detection method using color information that is obtained from the input image to the Projector and an image captured by a camera above the projection display. After pixel correspondences between the two images are found by calibrating the geometry distortion and color distortion, the natural color variations are estimated for the projection display. Then, any pixel that has another variation not resulting from natural geometry or color distortion is considered a part of foreground objects, because a foreground object in a projection display changes the values of pixels. As shown by experimental results, the proposed foreground detection method is applicable to an interactive projection display system such as the DigitalDesk

Small Scale Map Projection and Coordinate System Improvement in Consideration of Usability and Compatibility

  • Choi, Byoung Gil;Na, Young Woo;Jung, Jin Woo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.34 no.2
    • /
    • pp.171-183
    • /
    • 2016
  • Small-scale maps currently used are made by scanning and editing printed maps and its shortcoming is accumulated errors at the time of editing and low accuracy. TM projection method is used but its accuracy varies. In addition, small-scale maps are made without consideration of usability and compatibility with other scale maps. Therefore, it is necessary to suggest projection and coordinates system improvement methods in consideration of usability and compatibility between data. The results of this study reveal that in order to make the optimum small-scale map, projection that fits the purpose of map usage in each scale, coordinate system and neat line composition should be selected in consideration of interrelation and compatibility with other maps. Conic projection should be used to accurately illustrate the entire country, but considering usability and compatibility with other maps, traversing cylindrical projection should be used instead of conic projection. For coordinates system of the small-scale map, Universal Transverse Mercator (UTM-K) based on the World Geodetic System should be used instead of conventional longitude and latitude coordinate system or Transverse Mercator.

Algorithm Selection Method for Efficient Maximum Intensity Projection Based on User Preference (사용자 선호에 기반한 효율적 최대 휘소 가시화 알고리즘의 선택 방법)

  • Han, Cheol Hee;Kye, Heewon
    • Journal of Korea Multimedia Society
    • /
    • v.21 no.2
    • /
    • pp.87-97
    • /
    • 2018
  • Maximum intensity projection (MIP) is a common visualization technique in medical imaging system. A typical method to improve the performance of MIP is empty space leaping, which skips unnecessary area. This research proposes a new method to improve the existing empty space leaping. In order to skip more regions, we introduce a variety of acceleration strategies that use some tolerance given by the user to take part in image quality loss. Each proposed method shows various image quality and speed, and this study compares them to select the best one. Experimental results show that it is most efficient to add a constant tolerance function when the image quality required by the user is low. Conversely, when the user required image quality is high, a function with a low tolerance of volume center is most effective. Applying the proposed method to general MIP visualization can generate a relatively high quality image in a short time.