• Journal of Broadcast Engineering
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• v.13 no.4
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• pp.501-515
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• 2008

Recently, as users' requests for high quality mobile multimedia services are rapidly increasing and additional bandwidth can be provided by adopting the hierarchical modulation transmission technology, the research on the Advanced Terrestrial DMB (AT-DMB) service using the SVC (Scalable Video Coding) scheme is being actively studied. But, in order to realize a compatible video service and to accelerate the successful standardization and commercialization, it is necessary to simplify the compatible encoder structure. In this parer, we propose a fast mode decision method by constraining the redundant coding modes in the spatial scalable encoder that keeps the current T-DMB video in base layer. The proposed method is based on the statistical characteristics of each coding mode at both base and enhancement layers, inter-layer predictions, which are derived by investigating macroblock-layer coding modes of the spatial scalable encoder's functional structure. Through computer simulations, it is shown that a simplified encoder model that reduces the heavy computational burden can be found, while keeping the objective visual quality very high.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.2
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• pp.84-90
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• 2019

Tremendous computation of full search or lossless motion estimation algorithms for video coding has led development of many fast motion estimation algorithms. We still need proper control of computation and prediction quality. In the paper, we suggest an algorithm that reduces computation effectively and controls computational amount and prediction quality, while keeping prediction quality as almost the same as that of the full search. The proposed algorithm uses multiple thresholds for partial block sum and times of counting unchanged minimum position for each step. It also calculates the partial block matching error, removes impossible candidates early, implements fast motion estimation by comparing times of keeping the position of minimum error for each step, and controls prediction quality and computation easily by adjusting the thresholds. The proposed algorithm can be combined with conventional fast motion estimation algorithms as well as by itself, further reduce computation while keeping the prediction quality as almost same as the algorithms, and prove it in the experimental results.

• Journal of Broadcast Engineering
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• v.13 no.3
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• pp.411-414
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• 2008

In this paper, we present a determination method of quantization skipping condition for H.264/AVC video encoding standard. In order to reduce the complexity of quantization process that is coming from Integer discrete cosine transform, a quantization skipping condition is derived by the analysis of integer transform and quantization processes. The experimental results show that the proposed algorithm has the capability to reduce the computational complexity of CPU operation time about 10-25(%)

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.8
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• pp.1976-1988
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• 1996

This paper describes TCM(trellis coded modulation) schemes using 32VSB signal for digital CATV system. First we design optimum encoder with code rate 4/5 for 32VSB by using one dimenstional signal constellation and obtain 0.75-4.38 dB coding gains over the existing uncoded 16VSB. Second by using two dimensional signal constellation we design TCM encoders with code rate 9/10, which are better in the power efficienty (0.5-2.27 dB) and the transmission rate(12.5%), and we also design TCM encoders which have more coding gains than one dimensional TCM encoders for the larger number of states(more than 8 states).

• Journal of the Korea Society of Computer and Information
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• v.4 no.4
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• pp.1-8
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• 1999

In the logic where we study the principle and method of human, the binary logic with the proposition which has one-valued property that it can be assigned the truth value 'truth'or 'false'. Although most of the traditional binary logic which was drawn by human includes fuzziness hard to deal with, the knowledge for expressing it is not precise and has less degree of credit. This study uses multi-valued logic in order to slove the problem above that .When compared with the data processing ability of the binary logic, Multi-valued logic has an at a high speed. Therefore the Inference can be possible by minimization multi-valued logic in stead of using the information stead of using the information system based on the symbolic binary logic.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.5-7
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• 2018

VLSI(Very large scale integration) 기술을 통한 트랜지스터의 소형화를 통해 CMOS 집적 회로의 성능은 지속적으로 발전해 왔다. 이와 같은 기술 발전에 따라 집적 회로를 구성하는 디지털 논리 요소 또한 진화를 하고 있다. 디코더는 부호화된 정보를 다시 부호화되기 전으로 되돌아가는 처리를 하는 디지털 논리 요소이며 컴퓨터 설계에서 많이 사용되는 핵심 요소이다. 본 논문에서는 양자점 셀룰라 오토마타(Quantum Cellular-Automata, QCA)를 사용하여 인에이블 입력을 가진 2-to-4 디코더를 제안하였다. 4-입력 유니버설 게이트의 하나의 입력을 1로 고정시켜 3-입력 NOR 게이트로 사용하며, 입력 값 X와 입력 값 Y의 중복된 배선 수를 감소시키고 한 배선으로 두 게이트에 입력을 연결하여 디코더의 배선 수와 배선 교차부를 최소화한다. 제안안하는 4-to-2 인에이블 디코더는 기존 디코더보다 셀의 개수와 클럭수를 감소시켜 디코더의 성능을 더 효율적으로 향상시켰다. 이를 통해 고속 회로 설계에 활용 및 높은 성능을 기대 할 수 있으며 QCA 연구에 기여할 수 있을 것으로 전망 한다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.7
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• pp.42-49
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• 1989

A new integrated coding method is proposed in this study for embedding the text information including Hangul into an image. A monochrome analog image may be quantized to a few leveled digital image and be displayed on bi-leveled output devices by using halftone processing techniques. Text data are embedded on each micro pattern. Based on this concept, the encoding and the decoding algorithm are implemented and experiments are performed. As a result, the average amount of the embedded text information is more than 8 bpp (bits per pixer) in this halftone processed image converted form a $64{\times}64$ image, i.e, corresponding to 2000 characters in Hangul, or 4000 characters in alphanumeral. using this algorithm, the integrated personal record management system is implemented.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.10
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• pp.118-128
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• 2015

Compressive sensing (CS) has to face with two challenges of computational complexity reconstruction and low coding efficiency. As a solution, this paper presents a novel spatially scalable Kronecker two layer compressive sensing framework which facilitates reconstruction up to three spatial resolutions as well as much improved CS coding performance. We propose a dual-resolution sensing matrix based on the quincunx sampling grid which is applied to the base layer. This sensing matrix can provide a fast-preview of low resolution image at encoder side which is utilized for predictive coding. The enhancement layer is encoded as the residual measurement between the acquired measurement and predicted measurement data. The low resolution reconstruction is obtained from the base layer only while the high resolution image is jointly reconstructed using both two layers. Experimental results validate that the proposed scheme outperforms both conventional single layer and previous multi-resolution schemes especially at high bitrate like 2.0 bpp by 5.75dB and 5.05dB PSNR gain on average, respectively.

• Journal of Korea Multimedia Society
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• v.16 no.5
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• pp.539-548
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• 2013

Although Motion estimation (ME) plays an important role in digital video compression, it requires a complicated search procedure to find an optimal motion vector. Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. The computational complexity of motion estimation for Multi-view video coding increases in proportion to the number of cameras. To reduce computational complexity and maintain the image quality, a low complexity motion estimation search method is proposed in this paper. The proposed search method consists of four-grid diamond search patten, two-gird diamond search pattern and TZ 2 Point search pattern. These search patterns exploit the characteristics of the distribution of motion vectors to place the search points. Experiment results show that the speedup improvement of the proposed method over TZ search method (JMVC) can be up to 1.8~4.5 times faster by reducing the computational complexity and the image quality degradation is about to 0.01~0.24 (dB).

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.1
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• pp.19-27
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• 2001

The conventional fractal image compression based on wavelet transform has the disadvantage that the encoding takes many time, since it finds the optimum domain for all the range blocks. In this paper, we propose the fractal image compression based on wavelet transform using the SAS(Self Affine System) techniques. It consists of the range and domain blocks in the wavelet transform, and the range blocks select the domain which is located the relatively same position. In the encoding process, the proposed methods introduce SAS techniques that the searching process of the domains blocks is not required. Therefore, it can perform a fast encoding by reducing the computational complexity. And, the image quality is improved using the different scale factors for each level and the sub-tree in the decoding. As a result, the image quality and the compression ratio are adjustable by the scale factors.