• 제목/요약/키워드: Pixel Number

검색결과 436건 처리시간 0.028초

부호율 1/2인 변조부호의 픽셀당 레벨 수에 따른 홀로그래픽 데이터 저장장치 성능 분석 (Performance Analysis of Holographic Data Storage Depending on the Number of Levels Per Pixel of the Code Rate 1/2 Modulation Codes)

  • 정성권;이재진
    • 전자공학회논문지
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    • 제52권10호
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    • pp.16-20
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    • 2015
  • 본 논문에서는 차세대 저장장치로 주목받고 있는 멀티레벨 홀로그래픽 데이터 저장장치에서 여러 가지 레벨의 변조부호를 제안하고 이들의 성능을 알아본다. 멀티레벨 변조부호는 한 픽셀에 1비트 이상 저장이 가능하기 때문에 저장용량을 증가시킬 수 있으며, 동일한 픽셀 개수에서 더 많은 코드워드의 표현이 가능하다. 따라서 코드워드간 최소거리가 큰 변조부호를 만들 수 있으며 이런 성질은 오류정정 능력을 가지는 변조부호를 구성할 수 있다. 부호율을 1/2로 고정하고 제안된 변조부호들의 성능을 조사한 결과, 레벨 수가 커서 최소거리가 큰 변조부호의 성능보다 낮은 레벨이기 때문에 최소거리가 작은 변조부호가 더 좋은 성능을 보였다.

Performance analysis on the geometric correction algorithms using GCPs - polynomial warping and full camera modelling algorithm

  • Shin, Dong-Seok;Lee, Young-Ran
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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    • pp.252-256
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    • 1998
  • Accurate mapping of satellite images is one of the most important Parts in many remote sensing applications. Since the position and the attitude of a satellite during image acquisition cannot be determined accurately enough, it is normal to have several hundred meters' ground-mapping errors in the systematically corrected images. The users which require a pixel-level or a sub-pixel level mapping accuracy for high-resolution satellite images must use a number of Ground Control Points (GCPs). In this paper, the performance of two geometric correction algorithms is tested and compared. One is the polynomial warping algorithm which is simple and popular enough to be implemented in most of the commercial satellite image processing software. The other is full camera modelling algorithm using Physical orbit-sensor-Earth geometry which is used in satellite image data receiving, pre-processing and distribution stations. Several criteria were considered for the performance analysis : ultimate correction accuracy, GCP representatibility, number of GCPs required, convergence speed, sensitiveness to inaccurate GCPs, usefulness of the correction results. This paper focuses on the usefulness of the precision correction algorithm for regular image pre-processing operations. This means that not only final correction accuracy but also the number of GCPs and their spatial distribution required for an image correction are important factors. Both correction algorithms were implemented and will be used for the precision correction of KITSAT-3 images.

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플렉서블 액정 디스플레이를 위한 PDMS 기반 pixel-wall bonding 기술 (PDMS-based pixel-wall bonding technique for a flexible liquid crystal display)

  • 김영환;박홍규;오병윤;김병용;백경갑;서대식
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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    • pp.42-42
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    • 2008
  • Considerable attention has been focused on the applications of flexible liquid crystal (LC)-based displays because of their many potential advantages, such as portability, durability, light weight, thin packaging, flexibility, and low power consumption. To develop flexible LCDs that are capable of delivering high-quality moving images, like conventional glass-substrate LCDs, the LC device structure must have a stable alignment layer of LC molecules, concurrently support uniform cell gaps, and tightly bind two flexible substrates under external tension. However, stable LC molecular alignment has not been achieved because of the layerless LC alignment, and consequently high-quality images cannot be guaranteed. To solve these critical problems, we have proposed a PDMS pixel-wall based bonding method via the IB irradiation was developed for fasten the two substrates together strongly and maintain uniform cell gaps. The effect of the IB irradiation on PDMS with PI surface was also evaluated by side structure configuration and a result of x-ray photoelectron spectroscopic analysis of PDMS interlayer as a function of binder with substrates. large number of PDMS pixel-walls are tightly fastened to the surface of each flexible substrate and could maintain a constant cell gap between the LC molecules without using any other epoxy or polymer. To enhance the electro-optical performance of the LC device, we applied an alignment method that creates pretilt angle on the PI surface via ion beam irradiation. Using this approach, our flexible LCDs have a contrast ratio of 132:1 and a response time of about 15 ms, resulting in highly reliable electro-optical performance in the bent state, comparable to that of glass-substrate LCDs.

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픽셀 배치가 자유로운 임베디드 LED 전광판 모듈 및 제어장치 설계 (A Design of Embedded LED Display Board Module and Control Unit which the Placement of Pixels is Free)

  • 이배규;김정화
    • 전자공학회논문지
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    • 제50권10호
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    • pp.135-141
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    • 2013
  • 본 논문에서는 적색, 녹색, 청색의 세 가지 고휘도 LED를 하나의 소켓에 설치하여, 하나의 화소체 단위를 만들고, 이 화소체들의 조합과 다수 모듈들의 조합으로 문자, 그래픽, 동영상 등의 다양한 영상을 표출할 수 있는 풀컬러 전광판 모듈 및 제어장치를 개발하였다. LED 전광판 드라이버 모듈은 일정한 단위 면적에 RGB 픽셀을 조합한 도트에 드라이버 회로가 내장된다. 기존의 이러한 모듈형태는 특정 공간 및 설치 공간에 고정된 해상도를 구현하므로 가격이 높게 책정될 수 있다. 이러한 단점을 극복하기 위하여 임의의 피치 간격으로 배열이 자유로운 LED 드라이버 및 이에 따른 LED 픽셀 모듈을 개발하였다. 본 논문의 전광판 모듈은 기존 각각의 LED 모듈을 구동함에 있어서 병렬 방식의 데이터 처리 방식을 픽셀을 기준으로 그 위의 서브 모듈과 그 상위에 마스터 모듈의 개념을 도입하고 각각의 화소를 직병렬 통신 방식으로 개선함으로 인해서 처리할 수 있는 데이터의 속도를 초당 36프레임 이상으로 끌어올려서 상대적으로 데이터의 처리량이 많은 동화상의 경우에도 원활한 디스플레이를 할 수 있도록 하였다. 또한 기존 전광판의 깜박거림 현상이 개선되어 보다 선명한 영상이 제공되는 효과도 있다.

Wide Dynamic Range CMOS Image Sensor with Adjustable Sensitivity Using Cascode MOSFET and Inverter

  • Seong, Donghyun;Choi, Byoung-Soo;Kim, Sang-Hwan;Lee, Jimin;Shin, Jang-Kyoo
    • 센서학회지
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    • 제27권3호
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    • pp.160-164
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    • 2018
  • In this paper, a wide dynamic range complementary metal-oxide-semiconductor (CMOS) image sensor with the adjustable sensitivity by using cascode metal-oxide-semiconductor field-effect transistor (MOSFET) and inverter is proposed. The characteristics of the CMOS image sensor were analyzed through experimental results. The proposed active pixel sensor consists of eight transistors operated under various light intensity conditions. The cascode MOSFET is operated as the constant current source. The current generated from the cascode MOSFET varies with the light intensity. The proposed CMOS image sensor has wide dynamic range under the high illumination owing to logarithmic response to the light intensity. In the proposed active pixel sensor, a CMOS inverter is added. The role of the CMOS inverter is to determine either the conventional mode or the wide dynamic range mode. The cascode MOSFET let the current flow the current if the CMOS inverter is turned on. The number of pixels is $140(H){\times}180(V)$ and the CMOS image sensor architecture is composed of a pixel array, multiplexer (MUX), shift registers, and biasing circuits. The sensor was fabricated using $0.35{\mu}m$ 2-poly 4-metal CMOS standard process.

경계의 값 분포 특성과 정보를 기반한 새로운 경계 영상 압축 기법 (New Still Edge Image Compression based on Distribution Characteristics of the Value and the Information on Edge Image)

  • 김도현;한종우;김윤
    • 한국멀티미디어학회논문지
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    • 제19권6호
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    • pp.990-1002
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    • 2016
  • In this paper, we propose a new compression method for the edge image by analyzing the characteristics and the distribution of pixel values of the edge image. The pixel values of the edge image have the Gaussian distribution around '0', and most of the pixel values are `0`. By these analyses we suggest the Zero-Based codec that expresses all values in a CU by a single bit flag. Also, in order to reduce the computational complexity of the proposed codec, the block partition and the intra-prediction techniques are proposed by using edge information like the number of each edge direction, the distribution and the amplitude of a major edge direction in the CU. Experimental results show that the proposed codec leads to a slighter distortion in Y domain than that of HEVC, but has far faster processing speed up to 53 times while it maintains the similar image quality compared to HEVC.

Calibration of the depth measurement system with a laser pointer, a camera and a plain mirror

  • Kim, Hyong-Suk;Lin, Chun-Shin;Gim, Seong-Chan;Chae, Hee-Sung
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1994-1998
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    • 2005
  • Characteristic analysis of the depth measurement system with a laser, a camera and a rotating mirror has been done and the parameter calibration technique for it has been proposed. In the proposed depth measurement system, the laser beam is reflected to the object by the rotating mirror and again the position of the laser beam is observed through the same mirror by the camera. The depth of the object pointed by the laser beam is computed depending on the pixel position on the CCD. There involved several number of internal and external parameters such as inter-pixel distance, focal length, position and orientation of the system components in the depth measurement error. In this paper, it is shown through the error sensitivity analysis of the parameters that the most important parameters in the sense of error sources are the angle of the laser beam and the inter pixel distance. The calibration techniques to minimize the effect of such major parameters are proposed.

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마이크로 유동에서 PtOEP/PS 박막을 이용한 용존 산소 농도장의 정량적 가시화 (Quantitative Visualization of Dissolved Oxygen Concentration Field in Micro Flows using PtOEP/PS Membrane)

  • 송대헌;김현동;김경천
    • 한국가시화정보학회지
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    • 제9권1호
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    • pp.36-41
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    • 2011
  • It is highly needed to measure the dissolved oxygen (DO) concentration field in water for a variety of purposes such as biological, industrial, environmental monitoring and medical application. Application of PSP (Pressure Sensitive Paint) which is sensitive to oxygen concentration has been carried out to measure DO concentration field using PtOEP/PS film and intensity based method under the UV-LEDs illumination. A micro round water jet having 100% of DO was obliquely impinged on to a PtOEP/PS film coated plate placed in a 0% of DO water container. DO concentration fields on the impinging plate were quantitatively visualized with a $2.94\;{\mu}m$ of spatial resolution. Through pixel-by-pixel calibration, uncertainty of each pixel by different sensitivity, different dye concentration and non-uniformity of illumination was removed. It is demonstrated that the high DO concentration region was coincided with the impingement area. The DO concentration gradient due to DO diffusion was affected by Reynolds number.

Abdominal-Deformation Measurement for a Shape-Flexible Mannequin Using the 3D Digital Image Correlation

  • Liu, Huan;Hao, Kuangrong;Ding, Yongsheng
    • Journal of Computing Science and Engineering
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    • 제11권3호
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    • pp.79-91
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    • 2017
  • In this paper, the abdominal-deformation measurement scheme is conducted on a shape-flexible mannequin using the DIC technique in a stereo-vision system. Firstly, during the integer-pixel displacement search, a novel fractal dimension based on an adaptive-ellipse subset area is developed to track an integer pixel between the reference and deformed images. Secondly, at the subpixel registration, a new mutual-learning adaptive particle swarm optimization (MLADPSO) algorithm is employed to locate the subpixel precisely. Dynamic adjustments of the particle flight velocities that are according to the deformation extent of each interest point are utilized for enhancing the accuracy of the subpixel registration. A test is performed on the abdominal-deformation measurement of the shape-flexible mannequin. The experiment results indicate that under the guarantee of its measurement accuracy without the cause of any loss, the time-consumption of the proposed scheme is significantly more efficient than that of the conventional method, particularly in the case of a large number of interest points.

적응 정합 값 변환을 이용한 영상 모자이크 과정에서의 최적 Seam-Line 결정 (Optimal Seam-line Determination for the Image Mosaicking Using the Adaptive Cost Transform)

  • 전재춘;김형석
    • 대한전기학회논문지:시스템및제어부문D
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    • 제54권3호
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    • pp.148-155
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    • 2005
  • A seam-line determination algorithm is proposed to determine image border-line in mosaicing using the transformation of gray value differences and dynamic programming. Since visually good border-line is the one along which pixel differences are as small as possible, it can be determined in association with an optimal path finding algorithm. A well-known effective optimal path finding algorithm is the Dynamic Programming (DP). Direct application of the dynamic programming to the seam-line determination causes the distance effect, in which seam-line is affected by its length as well as the gray value difference. In this paper, an adaptive cost transform algorithm with which the distance effect is suppressed is proposed in order to utilize the dynamic programming on the transformed pixel difference space. Also, a figure of merit which is the summation of fixed number of the biggest pixel difference on the seam-line (SFBPD) is suggested as an evaluation measure of seamlines. The performance of the proposed algorithm has been tested in both quantitively and visually on various kinds of images.