• Title/Summary/Keyword: Frames of reference

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Using play-back image sequence to detect a vehicle cutting in a line automatically (역방향 영상재생을 이용한 끼어들기 차량 자동추적)

  • Rheu, Jee-Hyung;Kim, Young-Mo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.2
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    • pp.95-101
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    • 2014
  • This paper explains effective tracking method for a vehicle cutting in a line on the road automatically. The method employs KLT based on optical flow using play-back image sequence. Main contribution of this paper is play-back image sequence that is in order image frames for rewind direction from a reference point in time. The moment when recognizing camera can read a license plate very well can usually be the reference point in time. The biggest images of object traced can usually be obtained at this moment also. When optic flow is applied, the bigger image of the object traced can be obtained, the more feature points can be obtained. More many feature points bring good result of tracking object. After the recognizing cameras read a license plate on the vehicle suspected of cut-in-line violation, and then the system extracts the play-back image sequence from the tracking cameras for watching wide range. This paper compares using play-back image sequence as normal method for tracking to using play-forward image sequence as suggested method on the results of the experiment and also shows the suggested algorithm has a good performance that can be applied to the unmanned system for watching cut-in-line violation.

A Preliminary Study of Near Real-time Precision Satellite Orbit Determination (준 실시간 정밀 위성궤도결정을 위한 이론적 고찰)

  • Bae, Tae-Suk
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.1
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    • pp.693-700
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    • 2009
  • For real-time precise GPS data processing such as a long baseline network RTK (Real-Time Kinematic) survey, PPP (Precise Point Positioning) and monitoring of ionospheric/tropospheric delays, it is necessary to guarantee accuracy comparable to IGS (International GNSS Service) precise orbit with no latency. As a preliminary study for determining near real-time satellite orbits, the general procedures of satellite orbit determination, especially the dynamic approach, were studied. In addition, the transformation between terrestrial and inertial reference frames was tested to integrate acceleration. The IAU 1976/1980 precession/nutation model showed a consistency of 0.05 mas with IAU 2000A model. Since the IAU 2000A model has a large number of nutation components, it took more time to compute the transformation matrix. The classical method with IAU 2000A model was two times faster than the NRO (non-rotating origin) approach, while there is no practical difference between two transformation matrices.

Quasi-Lossless Fast Motion Estimation Algorithm using Distribution of Motion Vector and Adaptive Search Pattern and Matching Criterion (움직임벡터의 분포와 적응적인 탐색 패턴 및 매칭기준을 이용한 유사 무손실 고속 움직임 예측 알고리즘)

  • Park, Seong-Mo;Ryu, Tae-Kyung;Jung, Yong-Jae;Moon, Kwang-Seok;Kim, Jong-Nam
    • Journal of Korea Multimedia Society
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    • v.13 no.7
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    • pp.991-999
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    • 2010
  • In this paper, we propose a fast motion estimation algorithm for video encoding. Conventional fast motion estimation algorithms have a serious problem of low prediction quality in some frames. However, full search based fast algorithms have low computational reduction ratio. In the paper, we propose an algorithm that significantly reduces unnecessary computations, while keeping prediction quality almost similar to that of the full search. The proposed algorithm uses distribution probability of motion vectors and adaptive search patterns and block matching criteria. By taking different search patterns and error criteria of block matching according to distribution probability of motion vectors, we can reduces only unnecessary computations efficiently. Our algorithm takes only 20~30% in computational amount and has decreased prediction quality about 0~0.02dB compared with the fast full search of the H.264 reference software. Our algorithm will be useful to real-time video coding applications using MPEG-2 or MPEG-4 AVC standards.

An Intra Prediction Method and Fast Intra Prediction Method in Inter Frames using Block Content and Dependency Probabilities on neighboring Block Modes in H.264|AVC (영상 내용 특성과 주위 블록 모드 상관성을 이용한 H.264|AVC 화면 간 프레임에서의 화면 내 예측 부호화 결정 방법과 화면 내 예측 고속화 방법)

  • Na, Tae-Young;Lee, Bum-Shik;Hahm, Sang-Jin;Park, Chang-Seob;Park, Keun-Soo;Kim, Mun-Churl
    • Journal of Broadcast Engineering
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    • v.12 no.6
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    • pp.611-623
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    • 2007
  • The H.264|AVC standard incorporates an intra prediction tool into inter frame coding. However, this leads to excessive amount of increase in encoding time, thus resulting in the difficulty in real-time implementation of software encoders. In this paper, we first propose an early decision on intra prediction coding and a fast intra prediction method using the characteristics of block contents and the context of neighboring block modes for the intra prediction in the inter frame coding of H.264/AVC. Basically, the proposed methods determine a skip condition on whether the $4{\times}4$ intra prediction is to be used in the inter frame coding by considering the content characteristics of each block to be encoded and the context of its neighboring blocks. The performance of our proposed methods is compared with the Joint Model reference software version 11.0 of H.264|AVC. The experimental results show that our proposed methods allow for 41.63% reduction in the total encoding time with negligible amounts of PSNR drops and bitrate increases, compared to the original Joint Model reference software version 11.0.

Feature based Pre-processing Method to compensate color mismatching for Multi-view Video (다시점 비디오의 색상 성분 보정을 위한 특징점 기반의 전처리 방법)

  • Park, Sung-Hee;Yoo, Ji-Sang
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.15 no.12
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    • pp.2527-2533
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    • 2011
  • In this paper we propose a new pre-processing algorithm applied to multi-view video coding using color compensation algorithm based on image features. Multi-view images have a difference between neighboring frames according to illumination and different camera characteristics. To compensate this color difference, first we model the characteristics of cameras based on frame's feature from each camera and then correct the color difference. To extract corresponding features from each frame, we use Harris corner detection algorithm and characteristic coefficients used in the model is estimated by using Gauss-Newton algorithm. In this algorithm, we compensate RGB components of target images, separately from the reference image. The experimental results with many test images show that the proposed algorithm peformed better than the histogram based algorithm as much as 14 % of bit reduction and 0.5 dB ~ 0.8dB of PSNR enhancement.

Embedded SoC Design for H.264/AVC Decoder (H.264/AVC 디코더를 위한 Embedded SoC 설계)

  • Kim, Jin-Wook;Park, Tae-Geun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.45 no.9
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    • pp.71-78
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    • 2008
  • In this paper, we implement the H.264/AVC baseline decoder by hardware-software partitioning under the embedded Linux Kernel 2.4.26 and the FPGA-based target board with ARM926EJ-S core. We design several IPs for the time-demanding blocks, such as motion compensation, deblocking filter, and YUV-to-RGB and they are communicated with the host through the AMBA bus protocol. We also try to minimize the number of memory accesses between IPs and the reference software (JM 11.0) which is ported in the embedded Linux. The proposed IPs and the system have been designed and verified in several stages. The proposed system decodes the QCIF sample video at 2 frame per second when 24MHz of system clock is running and we expect the bitter performance if the proposed system is designed with ASIC.

Selective temporal error concealment method for H.264/AVC (H.264/AVC를 위한 선택적 시간축 에러 은닉 방법)

  • Jung Bongsoo;Choi Woongil;Jeon Byeungwoo;Kim Myung-Don;Choi Song-In
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.2 s.302
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    • pp.87-100
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    • 2005
  • In this paper, we propose a new selective temporal error concealment algerian best suited for H.264/AVC. The proposed algorithm performs selective temporal error concealment depending on whether the lost block is at background or foreground. It the corrupted macroblock is decided as at background, then the simple temporal replacement is performed. Also we propose replacing a lost block at foreground with the selective average of respectively estimated blocks from the multiple reference frames. This paper supposes error-corrupted H.264/AVC video bitstreams over CDMA2000 (or UMTS) air interface. It is shown that under Flexible Macroblock Ordering (FMO) coding of H.264/AVC, the proposed algorithm provides PSNR gain up to 1.18dB compared to built-in algorithm in the K264/AVC test model. In addition, the proposed error concealment method has average PSNR improvement of 0.33dB compared with that under N-slice coding mode. The proposed algorithm also provides better subjective video quality than other conventional error concealment algorithms.

Forward Vehicle Movement Estimation Algorithm (전방 차량 움직임 추정 알고리즘)

  • Park, Han-dong;Oh, Jeong-su
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.9
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    • pp.1697-1702
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    • 2017
  • This paper proposes a forward vehicle movement estimation algorithm for the image-based forward collision warning. The road region in the acquired image is designated as a region of interest (ROI) and a distance look up table (LUT) is made in advance. The distance LUT shows horizontal and vertical real distances from a reference pixel as a test vehicle position to any pixel as a position of a vehicle on the ROI. The proposed algorithm detects vehicles in the ROI, assigns labels to them, and saves their distance information using the distance LUT. And then the proposed algorithm estimates the vehicle movements such as approach distance, side-approaching and front-approaching velocities using distance changes between frames. In forward vehicle movement estimation test using road driving videos, the proposed algorithm makes the valid estimation of average 98.7%, 95.9%, 94.3% in the vehicle movements, respectively.

A Design of Fractional Motion Estimation Engine with 4×4 Block Unit of Interpolator & SAD Tree for 8K UHD H.264/AVC Encoder (8K UHD(7680×4320) H.264/AVC 부호화기를 위한 4×4블럭단위 보간 필터 및 SAD트리 기반 부화소 움직임 추정 엔진 설계)

  • Lee, Kyung-Ho;Kong, Jin-Hyeung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.6
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    • pp.145-155
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    • 2013
  • In this paper, we proposed a $4{\times}4$ block parallel architecture of interpolation for high-performance H.264/AVC Fractional Motion Estimation in 8K UHD($7680{\times}4320$) video real time processing. To improve throughput, we design $4{\times}4$ block parallel interpolation. For supplying the $10{\times}10$ reference data for interpolation, we design 2D cache buffer which consists of the $10{\times}10$ memory arrays. We minimize redundant storage of the reference pixel by applying the Search Area Stripe Reuse scheme(SASR), and implement high-speed plane interpolator with 3-stage pipeline(Horizontal Vertical 1/2 interpolation, Diagonal 1/2 interpolation, 1/4 interpolation). The proposed architecture was simulated in 0.13um standard cell library. The gate count is 436.5Kgates. The proposed H.264/AVC Fractional Motion Estimation can support 8K UHD at 30 frames per second by running at 187MHz.

A Design of 4×4 Block Parallel Interpolation Motion Compensation Architecture for 4K UHD H.264/AVC Decoder (4K UHD급 H.264/AVC 복호화기를 위한 4×4 블록 병렬 보간 움직임보상기 아키텍처 설계)

  • Lee, Kyung-Ho;Kong, Jin-Hyeung
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.5
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    • pp.102-111
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    • 2013
  • In this paper, we proposed a $4{\times}4$ block parallel architecture of interpolation for high-performance H.264/AVC Motion Compensation in 4K UHD($3840{\times}2160$) video real time processing. To improve throughput, we design $4{\times}4$ block parallel interpolation. For supplying the $9{\times}9$ reference data for interpolation, we design 2D cache buffer which consists of the $9{\times}9$ memory arrays. We minimize redundant storage of the reference pixel by applying the Search Area Stripe Reuse scheme(SASR), and implement high-speed plane interpolator with 3-stage pipeline(Horizontal Vertical 1/2 interpolation, Diagonal 1/2 interpolation, 1/4 interpolation). The proposed architecture was simulated in 0.13um standard cell library. The maximum operation frequency is 150MHz. The gate count is 161Kgates. The proposed H.264/AVC Motion Compensation can support 4K UHD at 72 frames per second by running at 150MHz.