• Title/Summary/Keyword: Video sequence

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Natural Language based Video Retrieval System with Event Analysis of Multi-camera Image Sequence in Office Environment (사무실 환경 내 다중카메라 영상의 이벤트분석을 통한 자연어 기반 동영상 검색시스템)

  • Lim, Soo-Jung;Hong, Jin-Hyuk;Cho, Sung-Bae
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.384-389
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    • 2008
  • Recently, the necessity of systems which effectively store and retrieve video data has increased. Conventional video retrieval systems retrieve data using menus or text based keywords. Due to the lack of information, many video clips are simultaneously searched, and the user must have a certain level of knowledge to utilize the system. In this paper, we suggest a natural language based conversational video retrieval system that reflects users' intentions and includes more information than keyword based queries. This system can also retrieve from events or people to their movements. First, an event database is constructed based on meta-data which are generated by domain analysis for collected video in an office environment. Then, a script database is also constructed based on the query pre-processing and analysis. From that, a method to retrieve a video through a matching technique between natural language queries and answers is suggested and validated through performance and process evaluation for 10 users The natural language based retrieval system has shown its better efficiency in performance and user satisfaction than the menu based retrieval system.

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Video Index Generation and Search using Trie Structure (Trie 구조를 이용한 비디오 인덱스 생성 및 검색)

  • 현기호;김정엽;박상현
    • Journal of KIISE:Software and Applications
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    • v.30 no.7_8
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    • pp.610-617
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    • 2003
  • Similarity matching in video database is of growing importance in many new applications such as video clustering and digital video libraries. In order to provide efficient access to relevant data in large databases, there have been many research efforts in video indexing with diverse spatial and temporal features. however, most of the previous works relied on sequential matching methods or memory-based inverted file techniques, thus making them unsuitable for a large volume of video databases. In order to resolve this problem, this paper proposes an effective and scalable indexing technique using a trie, originally proposed for string matching, as an index structure. For building an index, we convert each frame into a symbol sequence using a window order heuristic and build a disk-resident trie from a set of symbol sequences. For query processing, we perform a depth-first search on the trie and execute a temporal segmentation. To verify the superiority of our approach, we perform several experiments with real and synthetic data sets. The results reveal that our approach consistently outperforms the sequential scan method, and the performance gain is maintained even with a large volume of video databases.

Video Indexing for Efficient Browsing Environment (효율적인 브라우징 환경을 위한 비디오 색인)

  • Ko, Byong-Chul;Lee, Hae-Sung;Byun, Hye-Ran
    • Journal of KIISE:Software and Applications
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    • v.27 no.1
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    • pp.74-83
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    • 2000
  • There is a rapid increase in the use of digital video information in recent years. Especially, user requires the environment which retrieves video from passive access to active access, to be more efficiently. we need to implement video retrieval system including video parsing, clustering, and browsing to satisfy user's requirement. In this paper, we first divide video sequence to shots which are primary unit for automatic indexing, using a hybrid method with mixing histogram method and pixel-based method. After the shot boundaries are detected, corresponding key frames can be extracted. Key frames are very important portion because they help to understand overall contents of video. In this paper, we first analyze camera operation in video and then select different number of key frames depend on shot complexity. At last, we compose panorama images from shots which are containing panning or tilting in order to provide more useful and understandable browsing environment to users.

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Image Retrieval using Adaptable Weighting Scheme on Relevance Feedback (MPEG-2 비디오 스트림 편집시의 비트율 제어)

  • 윤범식;노홍진;최윤식
    • Journal of Broadcast Engineering
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    • v.5 no.2
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    • pp.188-198
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    • 2000
  • As MPEG-2 is introduced, a new editing system that works at the compressed domain is required. It is efficient to paste the two different video sequences in the compressed domain, but after repeated pasting, the result sequence can violate MPEG-2 rate control algorithm. In other words, it causes the underflow of the buffer during the decoding time. The earlier study inserted an additional fade-in sequence but it is not natural when we make a program. In this paper, a nobel method using requantization of the underflow sequence is presented.

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A Study on the MPEG-2 Coding Performance of 3D Endoscopic Image Sequence (3D 내시경 영상시컨스의 MPEG-2 코딩 효율에 관한 연구)

  • Song, C.G.;Lee, Y.M.;Lee, S.M.;Kim, W.K.;Lee, J.H.;Lee, M.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.84-87
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    • 1997
  • In this study, for the coding of stereoscopic video sequence, two approaches are presented based on simulcast mathod and sidefield image format. The field sequential method for stereoscopic visualization have been specified. Also, camera parameter and shooting conditions for each test sequence are studied. Coding method based on sidefield format structure revealed better performance over simulcast in PSNR.

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Direct Sequence Spread Spectrum Transmitter using FPGAs

  • Abhijit S. Pandya;Souza, Ralph-D′;Chae, Gyoo-Yong
    • Journal of information and communication convergence engineering
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    • v.2 no.2
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    • pp.76-79
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    • 2004
  • The DS-SS (Direct Sequence Spread Spec1nun) transmitter is part of a low data rate (∼150 kbps - burst rate and 64 bps - average data rate) wireless communication system. It is traditionally implemented using Digital Signal processing chip (DSP). However, with rapid increase in variety of services through cell phones, such as, web access, video transfer, online games etc. demand for higher rate is increasing steadily. Since the chip rate and thereby the sampling rate requirements of the system are fairly high, the transmitter should implemented using Field programmable Gate Arrays FPGAs instead of a DSP. This paper shows the steps taken to get a working prototype of the transmitter unit on a FPGA based platform.

Automatic Pedestrian Removal Algorithm Using Multiple Frames (다중 프레임에서의 보행자 검출 및 삭제 알고리즘)

  • Kim, ChangSeong;Lee, DongSuk;Park, Dong Sun
    • Smart Media Journal
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    • v.4 no.2
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    • pp.26-33
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    • 2015
  • In this paper, we propose an efficient automatic pedestrian removal system from a frame in a video sequence. It firstly finds pedestrians from the frame using a Histogram of Oriented Gradient(HOG) / Linear-Support Vector Machine(L-SVM) classifier, searches for proper background patches, and then the patches are used to replace the deleted pedestrians. Background patches are retrieved from the reference video sequence and a modified feather blender algorithm is applied to make boundaries of replaced blocks look naturally. The proposed system, is designed to automatically detect object and generate natural-looking patches, while most existing systems provide search operation in manual. In the experiment, the average PSNR of the replaced blocks is 19.246

A Fast Intra Skip Detection Algorithm for H.264/AVC Video Encoding

  • Kim, Byung-Gyu;Kim, Jong-Ho;Cho, Chang-Sik
    • ETRI Journal
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    • v.28 no.6
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    • pp.721-731
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    • 2006
  • A fast intra skip detection algorithm based on the ratedistortion (RD) cost for an inter frame (P-slices) is proposed for H.264/AVC video encoding. In the H.264/AVC coding standard, a robust rate-distortion optimization technique is used to select the best coding mode and reference frame for each macroblock (MB). There are three types of intra predictions according to profiles. These are $16{\times}16$ and $4{\times}4$ intra predictions for luminance and an $8{\times}8$ intra prediction for chroma. For the high profile, an $8{\times}8$ intra prediction has been added for luminance. The $4{\times}4$ prediction mode has 9 prediction directions with 4 directions for $16{\times}16$ and $8{\times}8$ luma, and $8{\times}8$ chrominance. In addition to the inter mode search procedure, an intra mode search causes a significant increase in the complexity and computational load for an inter frame. To reduce the computational load of the intra mode search at the inter frame, the RD costs of the neighborhood MBs for the current MB are used and we propose an adaptive thresholding scheme for the intra skip extraction. We verified the performance of the proposed scheme through comparative analysis of experimental results using joint model reference software. The overall encoding time was reduced up to 32% for the IPPP sequence type and 35% for the IBBPBBP sequence type.

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Adaptive Motion Vector Estimation Using the Regional Feature (영역별 특성을 이용한 적응적 움직임 벡터 추정 기법)

  • Park, Tae-Hee;Lee, Dong-Wook;Kim, Jae-Min;Kim, Young-Tae
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.502-504
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    • 1995
  • In video image compression, it is important to extract the exact notion information from image sequence in order to perform the data compression, the field rate conversion, and the motion compensated interpolation effectively. It is well known that the location of the smallest sum of absolute difference(SAD) does not always give the true motion vector(MV) since the MV obtained via full block search is often corrupted by noise. In this paper, we first classifies the input blocks into 3 categories : the background, the shade-motion, and the edge-motion. According to the characteristics of the classified blocks, multiple locations of relatively small SAD are searched with an adaptive search window by using the proposed method. The proposed method picks MVs among those candidates by using temporal correlation. Since temporal correlation reveals the noise level in a particular region of the video image sequence, we are able to reduce the search are very effectively.

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Hybrid Algorithm for Scene Change Detection of MPEG Sequence (MPEG 시퀸스의 장면 변화 검출을 위한 하이브리드 알고리즘)

  • Choe, Yoon-Sik;Lee, Joon-Hyoung
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.10
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    • pp.156-165
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    • 1998
  • In this paper, the hybrid algorithm for the scene change detection of MPEG-based compressed video data is proposed. There have been two methods to detect scene changes of video data compressed using algorithms such as MPEG or motion-JPEG: analyzing the compressed data directly, and analyzing from the retrieved data. The former has the advantage of taking less time, while the latter can obtain detail results at the expense of time and memory. Thus by combining each algorithm we detect cuts from compressed sequence, retrieve data for some selected region, and detect gradual scene changes. Simulation results verify the superiorities of the proposed algorithm in analyzing time and accuracy.

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