논문 : 해방이후의 이동영사 필름규격의 변화와 소멸에 대한 연구: 미군정기부터 1980년대까지

정승언 ( Seung Eon Jung ) 부산대학교 영화연구소 2011 아시아영화연구 Vol.4 No.1

이 연구는 한국영화에서 나타난 이동영사의 규격적 변화와 소멸에 관한 연구이다. 한국영화는 미군정기인 1947년부터 이전에는 등장하지 않았던 16mm 상업영화제작이 성행하게 되었고, 1956년에 다시 35mm로 표준화되는 현상을 보이게 된다. 1961년 이후 16mm 상업영화제작은 완전히 자취를 감추게 되지만 상영체계까지 모두 35mm로 전환되었던 것은 아니었다. 50년대 중반 이 후 신식 상설극장이 들어섰으나 이동영사에 사용되었던 필름은 대부분 16mm 규격이었다. 이동영사의 공식적 기록은 <아리랑>(1926)으로 이후에도 지속적으로 이루어지다가 일제 말기 정치적 목적을 지니면서 조직적으로 진행되기 시작하였고 미군정기와 동란기를 지나서 80년대 이동영사가 소멸되기 이전에는 8mm 이동영사도 등장하였다. 이러한 이동영사의 규격적인 변화와 소멸 원인을 살피고 규명하는 일은 분명 한국영화 연구에 작은 보탬이 될 수 있다. This study is for standard change of mobile projector and its extinction shown in Korean cinema. The mobile projector in a history of Korean cinema had been used very long time ago. The itinerant screening had been existed with a political ideology and finality in constant in terms of Korea history. For instance, the itinerant screening had been used for a tool of propaganda the end of Japanese colonization era to recruit volunteer and it had been used for an ideological tool of U.S. during the period of U.S. military government stay in Korea and postwar Korea. From the end of 1950s to early 1980s, it had been used for the means of anticommunism consciousness and politics. For the characteristic of the projector which required move around several areas with a few number of people, people preferred to use 16mm standard rather than to use 35mm one for the heavy weight and a lack of mobility. In 1956, standardization for projector had been decided to use 35mm but 16mm projector was represented for the standardization of mobile projector. However, a movement to use the 35mm projector from using 16mm one was occurred after the end of 1960s as not to lose customers as introducing the mobile projector vehicle which improved the mobility and techniques. In early 1970s, 8mm projector has been introduced which was able to use not only mobile projector but also Government PR film producing. Moreover, it settled in as a form of home movie with a personalization tendency. In 1980s, the various standards of projector and itinerant screening had been gradually disappeared for a leisure life, appearance of color television, VTR, popularization of various media and traffic development. The mobile projector in Korea is necessary to reilluminate based on a social and cultural background not by technological retrogression.

Projector Calibration for 3D Scanning Using Virtual Target Images

Hafeez Anwar,박강,Irfanud Din 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

In this work we propose a novel method to calibrate the projector. Calibration of the projector deals with the calculation of geometric parameters of the projector which are intrinsic and extrinsic parameters. An un-calibrated camera assists the process of finding the geometric parameters for projector. This method exploits the fact that a projector can be treated as inverse camera. The camera captures the scene and saves it as an image while the projector projects an image on the scene. Camera to projector transformation is used to make the projector able to see the calibration pattern. Then the projector is calibrated in a similar fashion like camera. Real data is used to evaluate the proposed method of projector calibration and good results are obtained.

인간의 시각 특성을 사용한 Multi-Projector Display에서의 밝기 향상 방법

이희원,이병욱,Lee Hee-Won,Lee Byung-Uk 한국통신학회 2006 韓國通信學會論文誌 Vol.31 No.5C

몰입감을 향상시키는 초대형 화면을 생성하기 위하여 여러 개의 프로젝터에서 투사되는 영상을 연결하여 마치 하나의 프로젝터에서 투사되는 영상처럼 보이게 하는 기술에 대한 연구가 활발히 진행 되고 있다. 각 프로젝터의 밝기는 그 모델이나 램프의 사용기간에 따라서 달라진다. 이를 보정하기 위하여 여러 프로젝터에서 투사된 영상들의 밝기를 균일하게 맞추는 일이 중요하다. 기존의 방법들은 프로젝터의 밝기 값만을 고려한 방법으로 밝기 보정을 하면 디스플레이 되는 화면이 어두워지는 경향이 있다. 본 논문에서는 프로젝터의 밝기만을 고려하던 기존의 밝기 보정 방법들과는 달리 프로젝터의 입력 영상의 밝기를 고려한 프로젝터의 밝기 보정방법을 제안하였다. 그 결과 기존의 방법들에 비해 멀티 프로젝터를 사용하여 스크린에 투사된 영상들의 밝기를 개선하여 자연스러운 영상을 얻을 수 있다. 이상의 과정을 simulation하여 그 동작을 확인하였고, 실제 영상에 적용하여 그 성능의 우수성을 입증하였다. Very large-area multi-projector display systems have wide applications since they provide immersible environments. The brightness of projectors in the system is different due to the design and aging of the bulbs, and optical properties of the projectors. Therefore it is imperative to match the brightness characteristics of projectors in the system. This issue has been addressed by many researchers. The state of the art solution considers characteristic of projector's brightness only. In this paper, we propose a method that takes into account brightness of projector as well as the dynamic range of the input image. We increase the dynamic range of the input image to utilize the maximum possible brightness of a projector while satisfying the spatial smoothness constraint. This achieves a seamless multi-display with dramatic brightness improvement.

구조광 방식 3차원 복원을 위한 간편한 프로젝터-카메라 보정 기술

박순용,박고광,Lei Zhang 한국정보처리학회 2010 정보처리학회논문지. 소프트웨어 및 데이터 공학 Vol.17 No.3

구조광(structured-light)을 이용한 3차원 복원 기술은 카메라 영상과 프로젝터 영상에서 구조광 코드(code)의 일치점을 탐색하고 그 점의 3차원 좌표를 획득하는 기술이다. 일치점의 3차원 좌표를 계산하기위해서는 카메라와 프로젝터의 보정(calibration)이 선행되어야 한다. 또한 복원된 3차원 형상의 정확도는 카메라와 프로젝터의 보정 결과에 영향을 받는다. 기존의 카메라-프로젝터 보정 기술은 고가의 장치를 사용하거나 복잡한 알고리즘을 사용하여 시간과 비용에 대한 효율성이 낮았다. 본 논문에서는 쉽고도 정밀한 카메라-프로젝터 보정 기술을 제안하고자 한다. 제안하는 기술은 복잡한 장치 또는 알고리즘이 필요치 않고 영상처리 기술로만 구현이 가능하기 때문에 3차원 형상복원의 효율성을 높일 수 있다. 두 종류의 카메라-프로젝터 장치에 대한 보정 실험 결과를 보였으며, 보정된 카메라와 프로젝터의 투영 오차 및 월드 기준점의 3차원 복원 오차를 측정하여 제안하는 알고리즘의 정밀도를 분석하였다. The structured-light 3D reconstruction technique uses a coded-pattern to find correspondences between the camera image and the projector image. To calculate the 3D coordinates of the correspondences, it is necessary to calibrate the camera and the projector. In addition, the calibration results affect the accuracy of the 3D reconstruction. Conventional camera-projector calibration techniques commonly require either expensive hardware rigs or complex algorithm. In this paper, we propose an easy camera-projector calibration technique. The proposed technique does not need any hardware rig or complex algorithm. Thus it will enhance the efficiency of structured-light 3D reconstruction. We present two camera-projector systems to show the calibration results. Error analysis on the two systems are done based on the projection error of the camera and the projector, and 3D reconstruction of world reference points.

서브픽셀분류를 활용한 프로젝터-카메라 대응관계 향상기법

임규제(Kyu Je Lim),박민기(Min Ki Park),이용이(Yong Yi Lee),최준호(Jun Ho Choi),이종훈(Jong Hoon Lee),이관행(Kwan H. Lee) (사)한국CDE학회 2015 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2015 No.동계

Projector-camera system is used for implementing spatial augmented reality which project virtual contents onto real object and 3D scanning. In this system, a gray code structured light sequence is used for encoding projector coordinate because a projector doesn’t take a picture like camera. And then, we set projectorcamera correspondence after decoding encoded projector coordinates for using captured images. However, we found incorrect set of projector-camera correspondence caused by effect of ambient light and strong interreflection from other surface patches. It leads to a result of incorrect 3D scanning. In this paper, we propose a method to improve projector-camera correspondence by using sub-pixel classification. Our method will improve projector-camera correspondence after classifying correct correspondence and incorrect correspondence automatically. The proposed method has advantages robust to varying threshold values in contrast to previous methods. And, it can be used to a variety of applications.

이동 프로젝터 투사영역의 폐회로 기반 위치추적에 의한 인터랙티브 투사

박지영(Ji-Young Park),이선민(Seon-Min Rhee),김명희(Myoung-Hee Kim) 한국정보과학회 2010 정보과학회논문지 : 소프트웨어 및 응용 Vol.37 No.1

본 연구에서는 영상을 대형으로 디스플레이 함과 동시에 사용자가 보다 세밀하게 관찰하고자하는 관심영역을 이동 프로젝터로 투사함으로써 개선된 해상도와 밝기로 디스플레이 하는 인터랙티브 투사 기법을 제안한다. 사용자는 이동 프로젝터를 들고 움직이며 관심영역의 위치를 변경하게 되는데 이 때 적절히 투사영상을 업데이트하기 위해 폐회로(closed-loop) 기반 추적 방법을 제안한다. 먼저 대형 디스플레이 영상에 이동 프로젝터의 위치를 나타내는 표시자를 삽입하고 이를 이동 프로젝터에 부착된 카메라로 획득한 연속영상에서 추출한다. 표시자의 중심이 항상 카메라 영상의 중심과 일치하도록 하는 제약조건 하에서 이를 만족시키기 위해 대형 디스플레이 상에서 표시자의 위치를 지속적으로 업데이트 한다. 이렇게 계산된 표시자의 위치에 해당하는 사각형 영역을 이동 프로젝터가 투사하게 되며 이때 카메라와 이동 프로젝터 사이의 투사변환을 적용하여 와핑한다. 표시자 분할은 총 네 단계로 이루어지며 카메라 영상에 대해 HSI 기반 전처리, 직선 탐지, 사각형 조건 검사, 교차비(cross-ratio) 검사를 거쳐 최종 네 개의 코너점이 결정된다. 제안된 투사 기법을 적용하여 구현한 인터랙티브 투사 시스템은 약 24fps의 처리속도를 지원하며 사용자 평가 결과 높은 유용성을 나타냈다. We propose an interactive projection technique to display details of a large image in a high resolution and brightness by tracking a portable projector. A closed-loop based tracking method is presented to update the projected image while a user changes the position of the detail area by moving the portable projector. A marker is embedded in the large image to indicate the position to be occupied by the detail image projected by the portable projector. The marker is extracted in sequential images acquired by a camera attached to the portable projector. The marker position in the large display image is updated under a constraint that the center positions of marker and camera frame coincide in every camera frame. The image and projective transformation for warping are calculated using the marker position and shape in the camera frame. The marker’s four corner points are determined by a four-step segmentation process which consists of camera image preprocessing based on HSI, edge extraction by Hough transformation, quadrangle test, and cross-ratio test. The interactive projection system implemented by the proposed method performs at about 24fps. In the user study, the overall feedback about the system usability was very high.

Canonical Projector Techniques for Analyzing Descriptor System

Zheng Zhang,Ngai Wong 제어·로봇·시스템학회 2014 International Journal of Control, Automation, and Vol.12 No.1

Physical systems are often naturally formulated as descriptor systems (DSs) which form a superset of the more restrictive standard state spaces. The analysis of a DS, however, is complicated by the algebraic coupling between its proper and improper subsystems. The recently emerging canonical projector technique, stemming from iterative matrix chain construction, provides a theoretically sound and numerically effective way to completely decouple these subsystems and largely facilitates the re-use or adaptation of standard state space techniques for DS analysis. Nonetheless, results concerning canonical projectors are scattered and their potential use is currently less appreciated. The objectives of this paper are twofold: i) It serves as a tutorial that collects distributed results about canonical projectors and presents them in a coherent manner; and more than just a tutorial, it elaborates and provides new/elegant/corrected proofs to some fundamental properties of canonical projectors. An iterative procedure for canonical projector construction, lacking in the literature, is also described. ii) Obvious applications, including some latest development, of projector techniques in practical circuit design problems are succinctly illustrated. By creating a self-contained repository of important canonical projector theories, it is hoped that more interest will be drawn and efficient numerical implementations will follow.

TEXTURE NEUTRALIZATION OF OBJECT USING A PROJECTOR-CAMERA SYSTEM

Chang Ok Yun,Young Bo Lee,Tae Soo Yun,Dong Hoon Lee 한국멀티미디어학회 2007 한국멀티미디어학회 국제학술대회 Vol.2007 No.-

Recently the use of the projectors has increased, for example performances use projectors for plays and musicals. But such performances offer only simple functions like projecting images and scene transformation by using a projector. Adding to these functions, we've proposed a novel method of performance for representing invisible objects. We have presented an algorithm for neutralizing the appearance of an arbitrary object using a projector-camera system. Our goal is to make the object look like it's a hidden object by projecting a carefully determined compensation image onto the object. We propose a simple and effective off-line projector-camera calibration by using homography. We measure radiometric parameters by using a basic algorithm of Smart Projector[1]. Since it is very efficient. it can also be used for temporal variation of the play and musical. The ability to neutralize the appearance of objects makes the projector a more versatile device that can be used to create experiences that are more realistic in the play and musical.

가정용 DLP 프로젝터의 소음 저감에 관한 연구

장동섭(Jang, Dong Seob),박철민(Park, Chul Min),박대경(Park, Dae Kyong) 한국소음진동공학회 2004 한국소음진동공학회 논문집 Vol.14 No.9

For the evaluation of acoustic noise of a DLP projector, vibration and sound characteristics of a DLP projector were studied. The acoustic noise of DLP projector could be classified into three categories, that is, the direct noise from a body of rotation, the air-bone noise generated from turbulence or vortex occurred during cooling process and the structural born noise produced by vibrating elements. Cooling fans and color filter wheel which rotates at 9000 rpm are main causes of acoustic noise induced in DLP projector. Since the structure of an optical module in a DLP projector can be excited by the excessive vibration of a color filter wheel, the structural design for anti-vibration should be considered. To make a reduction of overall acoustic noise, the anti-vibration design and the enclosing structure have been studied and applied to a color filter wheel.

Geometric Correction of Projected Images on Curved Surfaces using Unobtrusive Patterns

Jihui Ye,Junhee Park,Jiyoung Lee,Byung-Uk Lee 대한전자공학회 2017 IEIE Transactions on Smart Processing & Computing Vol.6 No.5

Video projectors are economical solutions for large-screen displays; they are employed for entertainment, education, and business presentations. As projectors have become more advanced, their applications have become numerous. Although the quality of projectors has improved recently, there is a fundamental requirement to have a flat screen for the display. In some circumstances, mobile projectors may have to use curved surfaces as a display option. To handle this situation, we propose applying a compensation method using a projector-camera system that senses spatial distortions in the projected images with a camera. The method presented estimates geometric distortions by embedding unobtrusive patterns that can identify distortion. This technique is especially suitable for mobile projectors where projectors and screens move relative to each other.