• Title/Summary/Keyword: Human visual system

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A Spatially Adaptive Post-processing Filter to Remove Blocking Artifacts of H.264 Video Coding Standard (H.264 동영상 표준 부호화 방식의 블록화 현상 제거를 위한 적응적 후처리 기법)

  • Choi, Kwon-Yul;Hong, Min-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.8C
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    • pp.583-590
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    • 2008
  • In this paper, we present a spatially adaptive post-processing algorithm for H.264 video coding standard to remove blocking artifacts. The loop filter of H.264 increases computational complexity of the encoder. Furthermore it doesn't clearly remove the blocking artifacts, resulting in over-blurring. For overcoming them, we combine the projection method with the Constraint Least Squares(CLS) method to restore the high quality image. To reflect the Human Visual System, we adopt the weight norm CLS method. Particularly pixel location-based local variance and laplacian operator are newly defined for the CLS method. In addition, the fact that correlation among adjoining pixels is high is utilized to constrain the solution space when the projection method is applied. Quantization Index(QP) of H.264 is also used to control the degree of smoothness. The simulation results show that the proposed post-processing filter works better than the loop filter of H.264 and converges more quickly than the CLS method.

HPV and Cervical Cancer Epidemiology - Current Status of HPV Vaccination in India

  • Chatterjee, Sharmila;Chattopadhyay, Amit;Samanta, Luna;Panigrahi, Pinaki
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.8
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    • pp.3663-3673
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    • 2016
  • Cervical cancer (CaCx) is the second most fatal cancer contributing to 14% of cancers in Indian females, which account for 25.4% and 26.5% of the global burden of CaCx prevalence and mortality, respectively. Persistent infection with high-risk human papilloma virus (HPV- strains 16 and 18) is the most important risk factor for precursors of invasive CaCx. Comprehensive prevention strategies for CaCx should include screening and HPV vaccination. Three screening modalities for CaCx are cytology, visual inspection with acetic acid, and HPV testing. There is no Indian national policy on CaCx prevention, and screening of asymptomatic females against CaCx is practically non-existent. HPV vaccines can make a major breakthrough in the control of CaCx in India which has high disease load and no organized screening program. Despite the Indian Government's effort to introduce HPV vaccination in the National Immunization Program and bring down vaccine cost, challenges to implementing vaccination in India are strong such as: inadequate epidemiological evidence for disease prioritization, duration of vaccine use, parental attitudes, and vaccine acceptance. This paper reviews the current epidemiology of CaCx and HPV in India, and the current status of HPV vaccination in the country. This article stresses the need for more research in the Indian context, to evaluate interventions for CaCx and assess their applicability, success, scalability and sustainability within the constraints of the Indian health care system.

Wavelet based data Watermarking (웨이브릿 기반의 데이터 워터마킹)

  • 김동현
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.6
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    • pp.1224-1228
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    • 2003
  • The use of digital imaging technique and digital contents based on internet has grown rapidly for last several years, and the needs of digital image protection become more important. For the purpose of copyright protection on digital image, the verification of authentication techniques like content authentication, ownership authentication, illegal copy and etc are needs. Digital watermarking, the invisible encryption technique to insert digital watermarking into image, the sophisticated perceptual information should be used for providing transparency and robustness of images on watermarking process. In this paper, we implement the algorithm for preventing forged attack. ownership protection and authentication by transforming the wavelet algorithms in frequency domain in terms of human visual system.

3D Depth Information Extraction Algorithm Based on Motion Estimation in Monocular Video Sequence (단안 영상 시퀸스에서 움직임 추정 기반의 3차원 깊이 정보 추출 알고리즘)

  • Park, Jun-Ho;Jeon, Dae-Seong;Yun, Yeong-U
    • The KIPS Transactions:PartB
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    • v.8B no.5
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    • pp.549-556
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    • 2001
  • The general problems of recovering 3D for 2D imagery require the depth information for each picture element form focus. The manual creation of those 3D models is consuming time and cost expensive. The goal in this paper is to simplify the depth estimation algorithm that extracts the depth information of every region from monocular image sequence with camera translation to implement 3D video in realtime. The paper is based on the property that the motion of every point within image which taken from camera translation depends on the depth information. Full-search motion estimation based on block matching algorithm is exploited at first step and ten, motion vectors are compensated for the effect by camera rotation and zooming. We have introduced the algorithm that estimates motion of object by analysis of monocular motion picture and also calculates the averages of frame depth and relative depth of region to the average depth. Simulation results show that the depth of region belongs to a near object or a distant object is in accord with relative depth that human visual system recognizes.

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Halftoning Method Using the Dispersed CMY Dithering and Blue Noise Mask (블루 노이즈 마스크와 분산 CMY 디더링을 이용한 하프토닝)

  • 김윤태;조양호;이철희;하영호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.1
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    • pp.1-9
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    • 2003
  • In this paper, we propose a new method dispersing spatially C(Cyan), M(Magenta), Y(Yellow) instead of K(black) in the bright region. The overlapping of black dots decreases brightness in the dark region, and black dots are very sensitive to human visual system in the bright region. Therefore, to avoid this problem, bright and dark gray region in the color image is considered in the proposed approach. A new method which uses CMY simultaneously in single mask is proposed, and CMY dots are used dispersing spatially for the bright region instead of black dot by this method. And tone curve connection is used to consider the gray level of dark region. In previous method, BNM (Blue Noise Mask) has high granularity and a narrow dynamic range. But the proposed method has the low granularity, wide dynamic range, and high contrast properties. Because the proposed method uses three times dots spatially in the different position than a conventional BNM, it can express more spatial information and a similar gray level compared with BNM.

Aesthetic Strategies in Steina and Woody Vasulka's Video Art (비디오아티스트 슈테이너 바술카와 우디 바술카의 미적 전략)

  • Lim, Shan
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.3
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    • pp.261-266
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    • 2020
  • As pioneers of the early video art, Steina Vasulka(1940-) and Woody Vasulka(1937-2019) had lead not only their own experimental arts, but also entire changes of contemporary avant-garde performance, music, and visual art. Two artists invented and developed electronic machines for video image-processing by collaborating with engineers, and performed creative experiment on transformation of digital image. For them, video art is not just a means of documentation. The Vasulkas' artistic practices were not bounded by conventional canons and rules in art world, and preferably were parts of active aesthetic strategies for coexistence of vision of human and vision of machine. Particularly, their video art recognized the video as the key medium in an era where media technology began to dominate the system of communication, and established artist's authority over manipulation of moving image electronically without depending on video camera. In that regard, we can value on their video art. Therefore, the paper reflects on the Vasulkas' art and life which have not yet been studied, and suggests academic interests in the context of their artistic activities and aesthetic strategies.

New Distance Measure for Vector Quantization of Image (영상 벡터양자화를 위한 편차분산을 이용한 거리계산법)

  • Lee, Kyeong-Hwan;Choi, Jung-Hyun;Lee, Bub-Ki;Cheong, Won-Sik;Kim, Kyoung-Kyoo;Kim, Duk-Gyoo
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.11
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    • pp.89-94
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    • 1999
  • In vector quantization (VQ), mean squared error (MSE) is widely used as a distance measure between vectors. But the distance between averages appears as a dominant quantity in MSE. In the case of image vectors, the coincidence of edge pattern is also important considering human visual system (HVS). Therefore, this paper presents a new distance measure using the variance of difference (VD) as a criterion for the coincidence of edge pattern. By using this in the VQ encoding, we can reduce the degradation of edge region in the reconstructed image. And applying this to the codebook design, we can obtain the final codebook that has a lot of various edge codevectors instead of redundant shade ones.

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Hierarchical Image Segmentation by Binary Split for Region-Based Image Coding (영역기반 영상부호화를 위한 이진 분열에 의한 계층적인 영상분할)

  • Park, Young-Sik;Song, Kun-Woen;Han, Kyu-Phil;Lee, Ho-Young;Nam, Jae-Yeal;Ha, Yeong-Ho
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.8
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    • pp.68-76
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    • 1998
  • In this paper, a new morphological image segmentation algorithm of hierarchical structure by binary split is proposed. It splits a region with the lowest quality into two regions using only two markers having the highest contrast. Therefore, it improves the quality of image with limited regions and reduces contour information which is not sensitive to human visual system, when compared with the conventional algorithm. It is appropriate to PSTN, LAN, and mobile networks, of which the available transmission bandwidth is very limited, because the number of regions can be controlled. And the proposed algorithm shows very simple structure because it doesn't need post processing to eliminate small regions and reduces much computation by using only structuring element of small size at simplification step of each hierarchical structure when compared with the conventional algorithm.

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Head Mouse System Based on A Gyro and Opto Sensors (각속도 및 광센서를 이용한 헤드 마우스)

  • Park, Min-Je;Yoo, Jae-Ha;Kim, Soo-Chan
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.46 no.4
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    • pp.70-76
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    • 2009
  • We proposed the device to control a computer mouse with only head movements and eye blinks so that disabilities by car or other accidents can use a computer. The mouse position were estimated from a gyro-sensor which can measure head movements, and the mouse events such as click/double click were from opto sensors which can detect the eyes flicker, respectively. The sensor was mounted on the goggle in order not to disturb the visual field. There was no difference in movement speed between ours and a general mouse, but it required 3$\sim$4 more times in the result of the experiment to evaluate spatial movements and events detection of the proposed mouse because of the low accuracy. We could eliminate cumbersome work to periodically remove the accumulated error and intuitively control the mouse using non-linear relative point method with dead zones. Optical sensors are used in the event detection circuitry designed to remove the influence of the ambient light changes, therefore it was not affected in the change of external light source.

Emotion Recognition using Facial Thermal Images

  • Eom, Jin-Sup;Sohn, Jin-Hun
    • Journal of the Ergonomics Society of Korea
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    • v.31 no.3
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    • pp.427-435
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    • 2012
  • The aim of this study is to investigate facial temperature changes induced by facial expression and emotional state in order to recognize a persons emotion using facial thermal images. Background: Facial thermal images have two advantages compared to visual images. Firstly, facial temperature measured by thermal camera does not depend on skin color, darkness, and lighting condition. Secondly, facial thermal images are changed not only by facial expression but also emotional state. To our knowledge, there is no study to concurrently investigate these two sources of facial temperature changes. Method: 231 students participated in the experiment. Four kinds of stimuli inducing anger, fear, boredom, and neutral were presented to participants and the facial temperatures were measured by an infrared camera. Each stimulus consisted of baseline and emotion period. Baseline period lasted during 1min and emotion period 1~3min. In the data analysis, the temperature differences between the baseline and emotion state were analyzed. Eyes, mouth, and glabella were selected for facial expression features, and forehead, nose, cheeks were selected for emotional state features. Results: The temperatures of eyes, mouth, glanella, forehead, and nose area were significantly decreased during the emotional experience and the changes were significantly different by the kind of emotion. The result of linear discriminant analysis for emotion recognition showed that the correct classification percentage in four emotions was 62.7% when using both facial expression features and emotional state features. The accuracy was slightly but significantly decreased at 56.7% when using only facial expression features, and the accuracy was 40.2% when using only emotional state features. Conclusion: Facial expression features are essential in emotion recognition, but emotion state features are also important to classify the emotion. Application: The results of this study can be applied to human-computer interaction system in the work places or the automobiles.