• 한국통신학회논문지
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• 제27권6C호
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• pp.610-618
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• 2002

본 논문에서는 질러 공간과 블록영역 정보에 기반한 새로운 화상검색 방법을 제시한다. 각 화상에 대한 컬러 공간 정보는 컬러 이진세트에 의해 구해지고 블록영역 정보는 영역 세그멘테이션에 의해서 구해진다. 화상 검색 과정에서, 질의 화상과 데이터베이스 화상들의 컬러 및 화상 이진세트들을 비교하여 검색될 후보 화상의 집합을 결정한다. 특히, 유사도 측정 시 컬러 공간 분포와 객체의 블록영역 특징에 가중치를 고려한 검색이 가능하도록 하였다. 제안된 방법을 구현하고 6,000개의 화상들로 이루어진 화상 데이터베이스에 대해 적용함으로써 컬러 공간 및 블록영역특징을 이용한 화상 검색이 매우 효과적임을 보였다.

• 한국컴퓨터정보학회논문지
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• 제25권10호
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• pp.1-14
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• 2020

이 논문에서는 낸드 플래시 메모리 기반 저장장치를 기존 섹터 기반 파일시스템에서 사용할 때 사상정보 관리개수의 증가로 인해 시스템 메모리 사용량이 증가하는 문제를 최대한 해결하기 위해 데이터 입출력 시 시간적집약성과 공간적집약성을 함께 고려한 사상기법을 제안한다. 제안기법은 색인 블록을 기반으로 페이지 단위로 사상정보만을 저장하여 이를 블록단위로 관리한다. 제안기법은 이를 위해 스몰 블록 내 하나에 페이지에 다수의 사상정보를 저장하여 관리하기 위한 순차 오프셋을 이용하며 블록 내에서 사상정보에 변경에 대응하는 여유페이지를 위한 역순 오프셋을 이용한다. 제안기법은 이를 통해 기존기법과 비교하여 블록단위 삭제 횟수가 적게 발생하며 사상정보 관리를 위해 필요한 시스템메모리 사용량이 낮은 장점이 있다 제안기법에 색인 블록 사상기법은 기존 로그블록 기법과 비교하여 블록병합 횟수를 약 32% 줄였다.

• 정보처리학회논문지B
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• 제14B권5호
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• pp.361-368
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• 2007

본 논문은 비디오 영상에서 블록기반 차영상을 이용한 연기검출 방법을 제시한다. 제안된 방법은 배경으로부터 변경된 영역 검출 단계, 배경영상 갱신단계, 검출된 영역이 연기인지를 판단하는 단계의 세 단계로 구성된다. 입력 비디오에서 각 프레임의 블록 평균영상을 계산하였으며, 변화영역을 검출하기 위하여 배경영상의 블록평균영상과 입력영상의 블록평균영상의 차이를 사용한다. 블록기반 차영상을 투영하여 변화된 사각영역을 검출한다. 차영상의 투영을 이용한 배경블록평균영상의 갱신방법을 제안한다. 변화영역의 중심위치 및 YUV 색상의 시간적 특징을 이용하여 연기영역을 판단한다.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.886-892
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• 2022

In construction projects, it is common to exchange documents using email because of convenience. In this study, a method extracting and organizing block information automatically based on email was developed. This method is composed of document exchange and archiving processes, which are difficult to manage and vulnerable to loss. Therefore, this study aims to develop a solution that can automatically link email and block information. The block data components are designed to derive from email exchange and user-additional input information. Also, automatically generating blocks process including extraction and conversion of information was proposed. This solution can lead to promote the convenience of project document management in terms of identifying the document flow and preventing loss of information.

• 한국통신학회논문지
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• 제21권6호
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• pp.1361-1369
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• 1996

Motion estimation is one of the key components for high quality video coding. In this paper, a new motion estimation scheme for MPEG-like video coder is suggested. The proposed temporally adaptive motion estimation scheme consists of five functional blocks: Temporal subband analysis (TSBA), extraction of temporal information, scene change detection (SCD), picture type replacement (PTR), and temporally adapted block matching algorithm (TABMA). Here all the functional components are based on the temporal subband analysis. In this papre, we applied the analysis part of subband decompostion to the temporal axis of moving picture sequence, newly defined the temporal activity distribution (TAD) and average TAD, and proposed the temporally adapted block matching algorithm, the scene change detection algorithm and picture type replacement algorithm which employed the results of the temporal subband analysis. A new block matching algorithm TABMA is capable of controlling the block matching area. According to the temporal activity distribution of objects, it allocates the search areas nonuniformly. The proposed SCD and PTR can prevent unavailable motion prediction for abrupt scene changes. Computer simulation results show that the proposed motion estimation scheme improve the quality of reconstructed sequence and reduces the number of block matching trials to 40% of the numbers of trials in conventional methods. The TSBA based scene change detection algorithm can detect the abruptly changed scenes in the intentionally combined sequence of this experiment without additional computations.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1991년도 추계종합학술발표회논문집
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• pp.81-85
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• 1991

In this paper, we present a motion compensated video compression method based on both block and object motions. A simplified objectoriented motion parameter is estimated from the block based motion vectors. A decision rule for the global or local MCP modes is established. Simulation results show that the proposed method has lower bit-rates than the BMA based method at the same reconstruction errors.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.2108-2111
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• 2003

This paper introduces a new local feature extraction method and image matching method for the localization and classification of targets. Proposed method is based on the block-by-block projection associated with directional pattern of blocks. Each pattern has its own eigen-vertors called as CEBs(Classified Eigen-Blocks). Also proposed block-based image matching method is robust to translation and occlusion. Performance of proposed feature extraction and matching method is verified by the face localization and FLIR-vehicle-image classification test.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.2351-2354
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• 2003

A new transform coder for arbitrarily shaped image segments is proposed. In the encoder, a block-based DCT is applied to the resulting image block after shifting pixels within the image segment to block border and padding the mean value of the pixels to empty region. For reducing the transmission bit rate, the transform coefficients located in padded region are truncated and only the remaining transform coefficients are transmitted to the decoder. In the decoder, the transform coefficients truncated in the encoder are recovered using received transform coefficients and a block-based inverse DCT is performed.

• Journal of Communications and Networks
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• 제12권1호
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• pp.5-10
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• 2010

This paper introduces a new fast motion estimation based on estimating a block matching error (i.e., sum of absolute difference (SAD)) between blocks which can eliminate an impossible candidate block much earlier than a conventional partial distortion elimination (PDE) scheme. The basic idea of the proposed scheme is based on predicting the total SAD of a candidate block using its partial SAD. In particular, in order to improve prediction accuracy and computational efficiency, a sub-sample based block matching and a selective pixel-based approaches are employed. In order to evaluate the proposed scheme, several baseline approaches are described and compared. The experimental results show that the proposed algorithm can reduce the computations by about 44% for motion estimation at the cost of 0.0005 dB quality degradation versus the general PDE algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권2호
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• pp.366-385
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• 2013

In this paper, we propose a compressed sensing (CS) based Wyner-Ziv (WZ) codec using motion-aligned auto regressive model (MAAR) based side information (SI) extrapolation to improve the compression performance of low-delay distributed video coding (DVC). In the CS based WZ codec, the WZ frame is divided into small blocks and CS measurements of each block are acquired at the encoder, and a specific CS reconstruction algorithm is proposed to correct errors in the SI using CS measurements at the decoder. In order to generate high quality SI, a MAAR model is introduced to improve the inaccurate motion field in auto regressive (AR) model, and the Tikhonov regularization on MAAR coefficients and overlapped block based interpolation are performed to reduce block effects and errors from over-fitting. Simulation experiments show that our proposed CS based WZ codec associated with MAAR based SI generation achieves better results compared to other SI extrapolation methods.