• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.1042-1046
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• 2000

본 논문에서는 질감 정보를 나타낼 수 있는 Block-based 에지 히스토그램과 색상 정보를 표현할 수 있는 DCT 를 이용한 칼라 영상 검색 방법을 제안한다. 제안된 방법은 최소의 특징량으로 최대의 검색효율을 얻기 위해 YCbCr 칼라 모델상에서 Y 영상으로부터는 전체적인 영상에 대한 히스토그램과 에지 히스토그램을 특징량으로 추출하고 Cb, Cr 영상으로부터는 DCT 계수를 특징량으로 추출하여 칼라 영상을 검색한다. 이는 칼라와 질감을 동시에 고려하면서 특징량의 크기가 적어 웹, 대용량 검색 시스템 및 동영상 검색에 적합하다. 성능 평가는 MPEG-7 의 칼라 특징자들의 성능평가를 위해 사용된 S1 및 S3 그룹 영상을 대상으로 실험하였으며 제안한 복합 특징량은 칼라 영상 검색에서 우수한 성능을 나타냄을 실험으로 확인 하였다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.3
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• pp.193-202
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• 2010

This paper presents a high-speed low-complexity pipelined Reed-Solomon (RS) (255,239) decoder using pipelined reformulated inversionless Berlekamp-Massey (pRiBM) algorithm and its folded version (PF-RiBM). Also, this paper offers efficient pipelining and folding technique of the RS decoders. This architecture uses pipelined Galois-Field (GF) multipliers in the syndrome computation block, key equation solver (KES) block, Forney block, Chien search block and error correction block to enhance the clock frequency. A high-speed pipelined RS decoder based on the pRiBM algorithm and its folded version have been designed and implemented with 90-nm CMOS technology in a supply voltage of 1.1 V. The proposed RS(255,239) decoder operates at a clock frequency of 700 MHz using the pRiBM architecture and also operates at a clock frequency of 750 MHz using the PF-RiBM, respectively. The proposed architectures feature high clock frequency and low-complexity.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.177-184
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• 2002

In these day, the storage capacity has been growing and the informations increase in geometrically progression in a modem information age. At present the situation is required that the exchanges and access of the informations is available without regard to time and space. In this paper we present a effective backup systems to backup the information of server that continuously has to be accessible in 365's days. There are two backup cases. one is a file-base backup and the other is a block-based backup. In general, a block-based backup has a good performance than a file-based backup but it is difficult to implement a block-based systems. First, we introduce the technique of backup and methods, on-line backup. Next, we present our backup systems based on client-server model and have a snapshot facility. Finally we introduce SCSI-Protocol in order to increase the data transfer rate.

• Journal of Internet Computing and Services
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• v.21 no.3
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• pp.93-102
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• 2020

In order for data obtained through all stages of digital crime investigation to be recognized as evidence capability, it must satisfy legal / technical requirements. In this paper, we propose a mechanism and implement software to provide digital forensic evidence by automatically recovering files by scanning / inspecting the unallocated area inside the storage disk block without relying on information provided by the file system. The proposed technique checks / analyzes the RAW disk data of the system under analysis in 512-byte block units based on information on the storage format / file structure of various files stored on the disk without referring to the file system-related information provided by the operating system. The file carving process was implemented, and a smart carving mechanism was proposed to intelligently restore deleted or damaged files in the storage device. As a result, we have provided a block based smart carving method to intelligently identify fragmented and damaged files in storage efficiently for forgery analysis on digital forensic investigation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7B
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• pp.1378-1383
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• 1999

In this paper, an effective variable-block-based image compression technique using wavelet transform is proposed. Since the statistical property of each wavelet subband is different, we apply the adaptive quantization to each wavelet subband. In the proposed algorithm, each subband is divided into non-overlapping variable-sized blocks based on directional properties. In addition, we remove wavelet coefficients which are below a certain threshold value for coding efficiency. To compress the transformed data, the proposed algorithm quantizes the wavelet coefficients using scalar quantizer in LL subband and vector quantizers for other subbands to increase compression ratio. The proposed algorithm shows improvements in compression ratio as well as PSNR compared with the existing block-based compression algorithms. In addition, it does not cause any blocking artifacts in very low bit rates even though it is also a block-based method. The proposed algorithm also has advantage in computational complexity over the existing wavelet-based compression algorithms since it is a block-based algorithm.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.907-910
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• 1998

In this paper, we present a comparative performance analysis of several blocking artifact reduction algorithms. For the performance analysis, we propose a block boundary region classification algorithm which classifies each horizontal and vertical block boundary into four regions using brightness change near the block boundary. The PSNR performance of each algorithm is compared. The MSE according to each block boundary region is also compared. Experimental results show that the wavelet transform based blocking artifact reduction algorithms have better performance over the other methods.

• Journal of Information Technology Services
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• v.2 no.2
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• pp.111-119
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• 2003

In this paper, an efficient block matching algorithm which is based on the Block Sum Pyramid Algorithm (BSPA) is presented. The cost of BSPA[1] was reduced in the proposed algorithm by using l2 norm and partial distortion elimination technique. Motion estimation accuracy of the proposed algorithm is equal to that of BSPA. The efficiency of the proposed algorithm was verified by experimental results.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.363-364
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• 2007

In this paper, we present a novel motion-compensated interpolation technique for non-moving caption region to prevent the block artifacts due to the failure of conventional block-based motion estimation algorithm on the block is consist of non-moving caption and moving object. Experimental results indicate good performance of the proposed scheme with significantly reduced block artifacts on image sequence that include non-moving caption. Also the proposed method is simple and adequate for hardware implementation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.12 no.3
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• pp.186-191
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• 2019

In this paper, we propose a implementation approach of the high-speed feature extraction algorithm. The proposed method is based on the block type classification algorithm which reduces the computation time when target macro block is divided to smooth block type that has no image features. It is quantitatively identified that occurs at 29.5% of the total image using 200 standard test images with $64{\times}64$ macro block size. This means that within a standard test image containing various image information, 29.5% can reduce the complexity of the operation. When the proposed approach is applied to the Canny edge detection, the required latency of the edge detection can be completely eliminated, such as 2D derivative filter, gradient magnitude/direction computation, non-maximal suppression, adaptive threshold calculation, hysteresis thresholding. Also, it is expected that operation time of the feature detection can be reduced by applying block type classification algorithm to various feature extraction algorithms in this way.

• Journal of Broadcast Engineering
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• v.22 no.5
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• pp.643-651
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• 2017

Steganography is one of information hiding technologies and discriminated from cryptography in that it focuses on avoiding the existence the hidden information from being detected by third parties, rather than protecting it from being decoded. In this paper, as an image steganography method which uses images as media, we propose a new block matching method that embeds information into the discrete wavelet transform (DWT) domain. The proposed method, based on a statistical analysis, reduces loss of embedding capacity due to inequable use of candidate blocks. It works in such a way that computes the variance of each candidate block, preserves candidate blocks with high frequency components while reducing candidate blocks with low frequency components by compressing them exploiting the k-means clustering algorithm. Compared with the previous block matching method, the proposed method can reconstruct secret images with similar PSNRs while embedding higher-capacity information.