• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.167-170
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• 2010

In this paper, we proposed a novel algorithm to detect the center of pupil in frontal view face. This algorithm, at first, extract an eye region from the face image using integral projection function and variance projection function. In an eye region, detect the center of pupil positions using circular hough transform with sobel edge mask. The experimental results show good performance in detecting pupil center from FERET face image.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.329-334
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• 2011

This paper presents improvement of compression rate for SPIHT algorithm based on wavelet compression through redundancy bit removing. Proposed SPIHT algorithm uses a method to select of optimized threshold from feature of wavelet transform coefficients and removes sign bit only if coefficient is LL area. Finally Proposed SPIHT algorithm applies to Huffman coding. Experimental results show that the proposed algorithm achieves more improvement bit rate and more fast progressive transmission with low bit rate.

• Annual Conference of KIPS
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• 2005.05a
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• pp.1445-1448
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• 2005

국내 디지털 방송 방식이 결정되고 본격적인 디지털 방송 서비스가 시행되면서, 전자프로그램가이드 (EPG: electronic program guide), 주식 및 일기예보등의 문자 방송이 활성화 되고 있다. 특히, 지상파 디지털 방송, 위성 방송, 및 최근 대두되고 있는 DMB (Digital Media Broadcasting) 지상파/위성 방송 등에서 기존의 단순 방송 서비스외에 양방향을 위한 새로운 서비스 개발을 확대하면서 문자방송의 역할은 점점 넓어지고 있다. 본 논문은 한글 데이터의 압축 방법에 관한 것으로, 디지털 방송의 문자 방송 서비스에서 사용되는 문자들을 효율적으로 압축하는 방법을 제안한다. 특히, 현재 서비스 되고 있는 방송의 문자 정보를 분석하고 한글의 특성과 글자간의 상관관계를 고려한 2 차 한글 허프만 부호 설계 기법을 제안한다. 본 논문에서 제안한 방법은 디지털 방송에서 점점 늘어나는 문자 방송의 문자를 효율적으로 압축함으로써 제한된 대역폭을 최대한 활용할 수 있는 방법을 제공한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5A
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• pp.545-553
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• 2004

Expansion of network environment and multimedia demand universality of application service as HDTV, etc. During these processes, it is essential to process multimedia in real time in the wireless communication system based on mobile phone network and in the wire communication system due to fiber cable and xDSL. So, in this Paper the optimal memory allocation algorithm combines the merit of huffman encoding which is superior in simultaneous decoding ability and lempel-ziv that is distinguished in execution of compress is proposed to improve the channel transmission rate and processing speed in the compressing procedure and is verified in the entropy encoder of HDTV. Because the entropy encoder system using proposed optimal memory allocation algorithm has memory saturation prevention we confirms that the compressing ratio for moving pictures is superior than Huffman encoding and LZW.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.1017-1027
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• 2000

In this paper, we propose a new coding method based on the distance between vertex segments for vertex positions in the vertex-based shape coding. The pixel lines are divided into the segments of a fixed length, and the segments that have vertex pixels are called vertex segments. We analyze the probability distribution of the relative distance between vertex segments and prove that it depends only on the ratio between the number of vertices and the number of segments. Considering the coding efficiency and implementation complexity, we choose a particular ratio to make a code table. For each input image, the segment size is chosen according tothe ratio, and the relative segment distances are entropy coded. It is shown that the proposed method is efficient for the images with many vertices.

• Journal of the Korea Society of Computer and Information
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• v.19 no.2
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• pp.31-37
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• 2014

In conventional methods for car navigational path detection using Hough transform, navigational path deviation of a car is decided in car navigational images with simple background. But in case of car navigational images having complex background with obstacles on the road, shadows, other cars, and so on, it is very difficult to detect navigational path because these obstacles obstruct correct detection of car navigational path. In this paper, I proposed an effective navigational path detection method having better performance than conventional navigational path detection methods using Hough transform only, and fuzzy binarization method and Canny mask are applied in the proposed method for the better performance. In order to evaluate the performance of the proposed method, I experimented with 20 car navigational images and verified the proposed method is more effective for detection of navigational path.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.1
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• pp.113-118
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• 2001

In this paper, we implement modules of the MPEG-2 AAC decoder using VHDL. Tools of Huffman decoder, inverse quantizer and high-density filter bank which are necessary for the AAC decoder. We designed the high speed Huffman decoder using the method of octal tree search algorithm, and reduced computational time of filter bank using IFFT. Also, we use table of computation result for an exponential calculation of Inverse quantizer in fixed-point hardware, and reduced the size of table using linear interpolation. Modules implemented by hardware through optimization work in real time at low clock frequency are possible to reduce the system size.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.11
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• pp.2094-2105
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• 1994

This paper contains a Hough transform based projection method derived from Radon transform for tracking dim unresolved(sub-pixel) moving targets that move along straight line parths across a time sequential image data. In contrast to several recently presented Hough transform methods using a compressed image referred to as the track map our proposed technique utilizing a set of projections taken along arbitrary orientations effectively increases the changes of target detection, and creates a robust track estimation environment by incorporating all the available knowledge obtained from the projections. Moreover, in order to quantitatively assess the estimation capability of the projection-based Hough transform algorithm, the analytical bounds on the Hough space parameter errors introduced by image space noise contamination are derived. The simulation yielded promising results of estimating the track parameters even under low signal to noise rations when our technique was tested against the time sequential sets of real infrared image data referred to as the HiCamps.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.2
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• pp.227-232
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• 2018

In a Hough transform that is a representative algorithm for the straight line detection, a great number of edge pixels generated from noisy or complex images cause enormous amount of computation and pseudo straight lines. This paper proposes a two step straight line detection algorithm to improve the conventional Hough transform. In the first step, the proposed algorithm divides an image into non-overlapping blocks and detects the information related to the straight line of the edge pixels in the block using a principal component analysis (PCA). In the second step, it detects the straight lines by performing the Hough transform limited slope area to the pixels associated with the straight line. Simulation results show that the proposed algorithm reduces average of ${\rho}$ computation by 94.6% and prevents the pseudo straight lines although some additional computation is needed.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.5
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• pp.596-600
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• 2010

This paper proposes hough transform-based semi-automatic vertex detection algorithm for object modeling on a mobile phone supporting touch-screens. The proposed algorithm shows fast processing time by searching the limited range of parameters for computing hough transform with a small range of ROI image. Moreover, the proposed algorithm removes bad candidates among the detected lines by selecting the two closest candidate lines from the position of user's input. After that, it accurately detects an interesting vertex without additionally required interactions by detecting an intersection point of the two lines. As a result, we believe that the proposed algorithm shows a 1.4 pixel distance error on average as a vertex detection accuracy under such conditions as a 5.7 pixel distance error on average as an inaccurate input.