• 한국통신학회논문지
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• 제38A권9호
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• pp.773-781
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• 2013

허프 변환은 데이터 손실 및 왜곡이 포함된 영상에서도 직선 정보 추출에 용이한 장점이 있어 컴퓨터 비전 분야의 응용분야에 널리 사용되어 왔다. 그러나 허프 변환의 보팅 과정은 비효율적인 연산구조와 많은 메모리 접근횟수로 인해 실시간 처리 임베디드 비전 시스템에 적용하는데 한계가 있다. 이에 본 논문에서는 허프 변환의 개선된 보팅 정책을 제시하고, 이를 적용하여 적은 하드웨어 자원 사용량으로 실시간 성능을 만족하는 허프 변환의 하드웨어 구조를 제안한다. 제안된 보팅 정책은 인접한 픽셀 간의 관계를 이용하여 보팅 연산 과정의 오버헤드를 줄였으며, 하드웨어 재사용성을 높임으로서 효율적인 연산구조를 가진다. 이러한 개선된 보팅 정책을 적용한 제안된 하드웨어 구조는 인접한 픽셀들의 보트 값을 병렬적으로 연산하고 저장하여 시간당 처리량을 높인다. 제안 구조의 장점은 순차적 연산 방식 대비 매우 적은 추가 하드웨어 자원만으로 이러한 성능 향상을 위한 병렬화를 달성한다는 것이다.

• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.2149-2154
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• 2015

This paper proposes a novel watermarking method to discover the tampers and localize it in digital image. The image which is to be used to generate a watermark is first wavelet decomposed and the edge feature from the sub bands of high frequency coefficients are retrieved to generate a watermark (Edge Feature Image) and which is to be embed on the cover image. Before embedding the watermark, the pixels of cover image are disordered through the Arnold Transform and this helps to upgrade the security of the watermark. The embedding of generated edge feature image is done only on the Least Significant Bit (LSB) of the cover image. The invisibleness and robustness of the proposed method is computed using Peak-Signal to Noise Ratio (PSNR) and Normalized Correlation (NC) and it proves that the proposed method delivers good results and the proposed method also detects and localizes the tampers efficiently. The invisibleness of proposed method is compared with the existing method and it proves that the proposed method is better.

• 한국통신학회논문지
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• 제25권10B호
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• pp.1832-1840
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• 2000

The error diffusion algorithm is good for reproducing continuous images to binary images. However the reproduction of edge characteristics is weak in power spectrum an analysis of display error. In this paper an edge enhanced error diffusion method is proposed to improve the edge characteristic enhancement. Spatial gradient information in original image is adapted for edge enhance in threshold modulation of error diffusion. First the horizontal and vertical second order differential values are obtained from the gradient of peripheral pixels(3x3) in original image. second weighting function is composed by function including absolute value and sign of second order differential values. The proposed method presents a good visual results which edge characteristics is enhanced. The performance of the proposed method is compared with that of the conventional edge enhanced error diffusion by measuring the edge correlation and the local average accordance over a range of viewing distances and the RAPSD of display error.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권2호
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• pp.1064-1079
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• 2019

Information security has become increasingly important with the rapid development of mobile devices and internet. An efficient encryption system is a key to this end. In this paper, we propose an image encryption method based on the cross diffusion of two chaotic maps. We use two chaotic sequences, namely the Logistic map and the Chebyshev map, for key generation which has larger security key space than single one. Moreover, we use these two sequences for further image encryption diffusion which decreases the correlation of neighboring pixels significantly. We conduct extensive experiments on several well-known images like Lena, Baboon, Koala, etc. Experimental results show that our algorithm has the characteristics of large key space, fast, robust to statistic attack, etc.

• 천문학회보
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• 제36권2호
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• pp.102.2-102.2
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• 2011

Sunspots usually appear in a group which can be classified by certain morphological criteria. In this study we examine the moments which are statistical parameters computed by summing over every pixels of contours, in order to quantify the morphological characteristics of a sunspot group. The moments can be additional characteristics to the sunspot group classification such as McIntosh classification. We are developing a program for image processing, detection of contours and computation of the moments using continuum images from SOHO/MDI. We apply the program to count the sunspot numbers from 303 continuum images in 2003. The sunspot numbers obtained by the program are compared with those by SIDC. The comparison shows that they have a good correlation (r=89%). We are extending this application to automatic sunspot classification (e.g., McIntosh classification) and flare forecasting.

• Journal of information and communication convergence engineering
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• 제11권1호
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• pp.50-55
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• 2013

In this paper, we propose a parallel intra-operation unit and a memory architecture for improving the performance of intra-prediction, which utilizes spatial correlation in an image to predict the blocks and contains 17 prediction modes in total. The design is targeted for portable devices applying H.264/AVC decoders. For boosting the performance of the proposed design, we adopt a parallel intra-operation unit that can achieve the prediction of 16 neighboring pixels at the same time. In the best case, it can achieve the computation of one luma $16{\times}16$ block within 16 cycles. For one luma $4{\times}4$ block, a mere one cycle is needed to finish the process of computation. Compared with the previous designs, the average cycle reduction rate is 78.01%, and the gate count is slightly reduced. The design is synthesized with the MagnaChip $0.18{mu}m$ library and can run at 125 MHz.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.42-45
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• 2003

This paper describes a new iris recognition method using shift-invariant subbands. First an iris image is preprocessed to compensate the variation of the iris image. Then, the preprocessed iris image is decomposed into multiple subbands using a shift invariant wavelet transform. The best subband among them, which have rich information for various iris pattern and robust to noises, is selected for iris recognition. The quantized pixels of the best subband yield the feature representation. Experimentally, we show that the proposed method produced superb performance in iris recognition.

• ETRI Journal
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• 제36권2호
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• pp.325-328
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• 2014

A modified version of Zhang's reversible data hiding method in encrypted images is proposed in this letter. To make full use of spatial correlation in natural images, the former idea of block division is thoroughly abandoned, whereas the random diffusion strategy is used. Additionally, the fluctuation measurement of pixels containing embedded data is improved by accurate prediction. The experiment results reveal that our proposed method is superior to both Zhang's method and the later improved version proposed by Hong and others.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.12-14
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• 2005

In this paper, we proposed an temporal error concealment (EC) using the proposed boundary matching method and the adaptive block matching method. The proposed boundary matching method improves the spatial correlation of the macroblocks (MBs) by reusing the pixels of the concealed MB to estimate a motion vector of a error MB. The adaptive block matching method inspects the horizontal edge and the vertical edge feature of a error MB surroundings, and it conceals the error MBs in reference to more stronger edge feature. This improves video quality by raising edge connection feature of the error MBs and the neighborhood MBs. In particular, we restore a lost MB as the unit of 8${\times}$16 block or 16${\times}$8 block by using edge feature from the surrounding macroblocks. Experimental results show that the proposed algorithm gives better results than the conventional algorithms from a subjective and an objective viewpoint.

• International journal of advanced smart convergence
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• 제12권2호
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• pp.67-75
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• 2023

Recently, many studies have been conducted on ways to utilize AI technology in NIDS (Network Intrusion Detection System). In particular, CNN-based NIDS generally shows excellent performance. CNN is basically a method of using correlation between pixels existing in an image. Therefore, the method of generating an image is very important in CNN. In this paper, the performance comparison of CNN-based NIDS according to the image generation method was performed. The image generation methods used in the experiment are a direct conversion method and a one-hot encoding based method. As a result of the experiment, the performance of NIDS was different depending on the image generation method. In particular, it was confirmed that the method combining the direct conversion method and the one-hot encoding based method proposed in this paper showed the best performance.