• Title/Summary/Keyword: Picture Quality

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Image Enhancement Using Error Diffusion with APL in PDP (APL 적용 오차 확산법을 이용한 PDP 화질 개선)

  • Jang Soo-Wook;Pyo Se-Jin;Lee Sung-Hak;Sohng Kyu-Ik;Kim Eun-Su
    • Journal of Korea Multimedia Society
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    • v.8 no.10
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    • pp.1360-1368
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    • 2005
  • PDP is the flat panel display, suitable for high definition television because of large-sire and high-brightness. It has many advantages such as fast response, wide viewing angle, low weight, and simple manufacturing process for fabrication. However, there are some disadvantages and one of them is the image quality degradation, which is dependent on the digital signal processing. Although image quality of PDP is improving by many researches and experimentations, it still isn't as good as that of CRT because of various factors. One of them is worm-like pattern generated by an error diffusion process. And the worm-like pattern is severely increased after an APL process. An increased worm-like pattern occur a drop of resolution in image and a change of CCT according to each grayscale. In this paper, a method for improvement of image quality using the error diffusion which considers the APL process is proposed. In the proposed method, the APL process is performed before the error diffusion process. Simulation results showed that the proposed method has better performances for resolution in images and CCT uniformity according to each grayscale than the conventional method.

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A Study on Measurement of Objective Image Quality by Scanning Type for MPEG-2-based Terrestrial 2HD Service and Application on Experimental Broadcasting (MPEG-2 기반 지상파 2HD 서비스를 위한 주사 방식별 객관적 화질 측정 및 시험방송 적용 연구)

  • Park, Sung-hwan;Chang, Hae-rang;Lee, Jong-su;Kwon, Soon-chul;Lee, Seung-hyun
    • Journal of Digital Contents Society
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    • v.16 no.2
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    • pp.275-282
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    • 2015
  • Since starting of terrestrial digital broadcasting in 2001, there has been discussion on introduction of multiple broadcasting services, one of advantages of digital broadcasting. In the mean time, task force on terrestrial multiple channel experimental broadcasting was formed with government organizations, broadcasting companies and household appliance companies in Oct. 2013, and terrestrial multiple channel experimental broadcasting was started between Jan. to April, 2014. Based on this experimental result, EBS started 2HD MMS experimental broadcasting first in Korea on Feb. 11, 2015. This study was carried out in consideration of operation of 2 HD channels in existing 6MHz bandwidth based on MPEG-2 codec with development of compression technology. A study on image quality optimization was carried out and applied to 2HD MMS experimental broadcasting through application experiment of variable bit rate and change according to 1080i and 720p scanning type.

A Comparative Study on Image Quality of Breast Image Tests using ACR Phantom (ACR 팬텀을 이용한 시스템별 유방검사 영상의 비교 연구)

  • Hong, Dong-Hee;Jung, Hong-Ryang;Lim, Cheong-Hwan
    • Journal of radiological science and technology
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    • v.29 no.4
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    • pp.241-247
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    • 2006
  • Recently, interests and utilization on Computed Radiography(CR) and Digital Radiography(DR) tends to increase owing to an introduction of Picture Archiving and Communication System(PACS) and an accuracy control of special medical equipment for a breast imaging examination. This study was intended to compare and analyze a detector's imaging quality by each system to be used for the breast imaging examination by using ACR Phantom used at the accuracy control. As an evaluation method, a significance and reliability of image's value using the ACR Phantom was analyzed by using SPSS program. The results are followed. 1. For the fiber, there was 3.9 score in Screen-Film, 4.2 score in CR($50{\mu}m$), 3.2 score in CR($100{\mu}m$), and 4.2 score in DR. There was the high score in the order of CR($50{\mu}m$), DR, Screen-Film, and CR($100{\mu}m$)(P<0.05). 2. For the calcification, there was 2.7 score in Screen-Film, 2.5 score in CR($50{\mu}m$), 2.0 score in CR($100{\mu}m$), and 2.9 score in DR. There was the high score in the order of DR, Screen-Film, CR($50{\mu}m$), and CR($100{\mu}m$).(0.025(P<0.05). 3. For Mass, there was 3.8 score in Screen-Film, 3.8 score in CR($50{\mu}m$), 3.6 score in CR($100{\mu}m$), and 4.5 score in DR. There was the high score in the order of DR, CR($50{\mu}m$), Screen-Film, and CR($100{\mu}m$) (P<0.1). 4. As the total score, there was 10.4 score in Screen-Film, 10.6 score in CR($50{\mu}m$), 8.7 score in CR($100{\mu}m$), and 11.3 score in DR. There was the high score in the order of DR, $CR(50{\mu}m$), Screen-Film, and $CR(100{\mu}m$). As shown in the above results, it can be known that DR and Screen-Film System has higher image quality than CR. But, DR has unstability caused by element, and Screen-Film has the low image quality caused by artifact as disadvantages. When Dual-Side CR($50{\mu}m$) was used among CR systems which had the problem of low image quality, it was indicated that there was no difference with Screen-Film System. Because the radiation imaging examination tends to become digitalized, each system for the breast imaging examination will need to be developed and supplemented.

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Largest Coding Unit Level Rate Control Algorithm for Hierarchical Video Coding in HEVC

  • Yoon, Yeo-Jin;Kim, Hoon;Baek, Seung-Jin;Ko, Sung-Jea
    • IEIE Transactions on Smart Processing and Computing
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    • v.1 no.3
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    • pp.171-181
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    • 2012
  • In the new video coding standard, called high efficiency video coding (HEVC), the coding unit (CU) is adopted as a basic unit of a coded block structure. Therefore, the rate control (RC) methods of H.264/AVC, whose basic unit is a macroblock, cannot be applied directly to HEVC. This paper proposes the largest CU (LCU) level RC method for hierarchical video coding in a HEVC. In the proposed method, the effective bit allocation is performed first based on the hierarchical structure, and the quantization parameters (QP) are then determined using the Cauchy density based rate-quantization (RQ) model. A novel method based on the linear rate model is introduced to estimate the parameters of the Cauchy density based RQ model precisely. The experimental results show that the proposed RC method not only controls the bitrate accurately, but also generates a constant number of bits per second with less degradation of the decoded picture quality than with the fixed QP coding and latest RC method for HEVC.

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Audio Signal Coding Using Wavelet Transform (웨이블렛 변환을 이용한 오디오 코딩)

  • Bae, Seok-Mo;Kim, Do-Hyoung;Chung, Jae-Ho
    • The Journal of the Acoustical Society of Korea
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    • v.16 no.4
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    • pp.64-70
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    • 1997
  • This paper is aimed to propose a new wavelet audio signal coding scheme which reduces the complexity of well-known MPEG(Moving Picture Expert Group)-Audio. The filters of MPEG0audio apply subband technique on the 16-bits PCM audio to aquire bitstream of subband sample using dynamic bit allocation. If we use the wavelet coefficients instead of subband samples and 6 bands which is less than 32 bands of MPEG-audio, the complexity can be reduced. A new audio signal compression algorithm in this paper is based on wavelet transform and the proposed algorithm is compared with MPEG-audio. At the bitrate of 256kbps, the proposed algorithm maintains the CD(Compact-disc) quality. We were able to reduce the about 40% of complexity at encoder and about 70% at decoder.

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Multi-stream Delivery Method of the Video Data Based on SPIHT Wavelet (SPIHT 웨이브릿 기반의 비디오 데이터의 멀티스트림 전송 기법)

  • 강경원;류권열;김기룡;문광석;김문수
    • Journal of the Institute of Convergence Signal Processing
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    • v.3 no.3
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    • pp.14-20
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    • 2002
  • In this paper, we proposed the compression technique of the video data using SPIHT(set partitioning in hierarchical trees) based on wavelet and the multi-stream delivery method for best-effort service as fully utilizing the clients bandwidth over the current Internet. The experiment shows that the proposed method provides about 1.5dB better picture quality without block effects than DCT(discrete consine transform) based coding schemes at the same bit rates because of using the wavelet video coder. In addition, this technique implements the multi-stream transmission based on TCP(transmission control protocol). Thus, it is provided with the best-efforts service which is robust to the network jitter problem, and maximally utilizes the bandwidth of the client's.

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Implementation of MDCT core in Digital-Audio with Micro-program type vector processor

  • Ku Dae Sung;Choi Hyun Yong;Ra Kyung Tae;Hwang Jung Yeun;Kim Jong Bin
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.477-481
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    • 2004
  • High Quality CD, OAT audio requires that large amount of data. Currently, multi channel preference has been rapidly propagated among latest users. The MPEG(Moving Picture Expert Group) is provides data compression technology of sound and image system. The MPEG standard provides multi channel and 5.1 sounds, using the same audio algorithm as MPEG-l. And MPEG-2 audio is forward and backward compatible. The MDCT (Modified Discrete Cosine Transform) is a linear orthogonal lapped transform based on the idea of TDAC(Time Domain Aliasing Cancellation). In this paper, we proposed the micro-program type vector processor architecture a benefit in MDCT/IMDCT of MPEG-II AAC. And it's reduced operating coefficient by overlapped area to bind. To compare original algorithm with optimized algorithm that cosine coefficient reduced $0.5\%$multiply operating $0.098\%$ and add operating 80.58\%$. Algorithm test is used C-language then we designed hardware architecture of micro-programmed method that applied to optimized algorithm. This processor is 20MHz operation 5V.

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The Improved Deblocking Algorithm for Low-bit Rate H.264/AVC (Low-bit Rate H.264/AVC 비디오에 적합한 개선된 디블럭킹 알고리즘)

  • Kwon, Dong-Jin;Kwak, Nae-Joung;Ryu, Sung-Pil
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.499-502
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    • 2006
  • H.264/MPEG4 Advanced Video coding joint standard needs deblocking filter of decoder. We propose a better deblocking algorithm ensuring picture quality even if it is low bit-rate and bandwidth in MPEG-4 video. The complexity diminishes in proposed deblocking algorithm because it uses only simple shift, addition and comparison. We handle dividing into complexity area, medium area and simple area after counting boundary intensity of mask block to identify presence of block effects. As a result of experiment, we make certain of that block effects reduces in proposed deblocking algorithm.

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Research and Development of High Performance 42-inch XGA Plasma Display Panel

  • Choi, Kwang-Yeol;Min, Byoung-Kuk;Kim, Tae-Hyung;Song, Byung-Soo;Yoo, Eun-Ho;Kim, Jin-Young;Jung, Yun-Kwon;Kim, Won-Tae;Yang, Hee-Chan;Ryu, Jae-Hwa
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.231-235
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    • 2004
  • High performance 42 inch XGA PDP with high luminance of 1,000 cd/$m^2$ has been developed using high efficient electrode structure, discharge gas and closed barrier ribs. For high speed addressing with single scan technique, address discharge time lag was reduced over 40% with FAST driving scheme and new materials. High dark room contrast ratio of 5,000 : 1 was achieved and picture quality was improved using new algorithm for eliminating false contour and improving gray level linearity.

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A Study on Middle-Aged People's Preparation for Old Age Life and Their Perception of Long-term Care Facilities (중년의 노후 생활준비도 및 요양시설 인식에 대한 연구)

  • Kim, Kwuy-Bun;Park, Min-Suk;Sok, So-Hyune R.
    • Research in Community and Public Health Nursing
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    • v.19 no.3
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    • pp.480-494
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    • 2008
  • Purpose: The study was to got basic data on the well-being of middle-aged people concerning their preparation for their upcoming old age and their quality of life. Methods: The subjects were 440 people aged between 40 and 59 living in Seoul and Gyeonggi-do. Results; First, Physical Preparation for old age was affected by religion, children, health, monthly income, and economical status, and these factors were shown statistically significant. Emotional preparation and spiritual Preparation were also related to the above-mentioned factors. Secondly, in the subjects' mental picture, a nursing home was a place for the aged without anyone who is going to take care of them and without abilities to care of themselves. Preference for nursing home was based on two factors. i.e., nursing and treatment care. and the cost was about one million won per month. Also they wanted that the government should pay a certain amount for private users. Conclusion: Therefore, people should lead a life of good health-related habits along with economical preparation for their old age.

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