• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.1
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• pp.105-111
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• 1990

In this paper, fast algorithms to generate the codebook of vector quantization in image coding, are proposed. And an efficient algorithm to guess a initial codebook, namely, binary splitting method, is proposed. We generated the initial codebook by binary splitting method and then reduced the searching time using Iterative Optimization algorithm as an alternate to the generalized Lloyd algorithm and several information from binary splitting method. And the searching time and performance can be traded off by varying the searching range. With this proposed algorithm, the computation time can be reduced by a factor of 60 Without any degradation of image quality.

• Journal of Korea Multimedia Society
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• v.16 no.7
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• pp.795-801
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• 2013

Recently, support vector machine has been widely used in various application fields due to its superiority of classification performance comparing with decision tree and neural network. Since support vector machine is basically designed for the binary classification problem, output coding method to analyze the classification result of multiclass binary classifier is used for the application of support vector machine into the multiclass problem. However, previous feature selection method for output coding based support vector machine found the features to improve the overall classification accuracy instead of improving each classification accuracy of each classifier. In this paper, we propose the novel feature selection method to find the features for maximizing the classification accuracy of each binary classifier in output coding based support vector machine. Experimental result showed that proposed method significantly improved the classification accuracy comparing with previous feature selection method.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.9
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• pp.76-84
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• 1999

EZW proposed by Shapiro is based on a zerotree constructed in a way that a parent coefficient in a subband is related to four child coefficients in the next finer subband of similar orientation. This fixed treeing based on 1-to-4 parent-child is suitable to exploti hierachical correlations among subbands but not to exploit spatial correlations within a subband. A new treeing by Joo, et al. is suggested to simulatneously exploit those two correlatins by extending parent-child relationship in a flexible way. The flexible treeing leads to increasing the number of symbols and lowering entorpy comparing to the fixed treeing, and therefore a better compression can be resulted. In this paper, we suggest two techniques to suppress the increasing of symbols. First, a probing bit is generated to avoid redundant scan for insignivicant coefficients. Second, since all subbands do not always require the same kind of symbol-set, produced symbols are re-symbolized into binary codes according to a pre-defined procedure. Owing to those techniques, all symbols are generated as binary codes. The binary symbols can be entropy-coded by an adaptive arithmetic coding. Moerover, the binary symbol stream can give comparatively good performances without help of additional entropy coding. Our proposed coding scheme is suggested in two modes: binary coding mode and arithmetic coding mode. We evaluate the effectivenessof our modifications by comparing with the original EZW.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.7
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• pp.61-68
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• 2008

In this paper, we propose an efficient hardware architecture and algorithm to increase an encoding process rate and implement a hardware for CABAC (Context Adaptive Binary Arithmetic Coding) which is used with one of the entropy coding ways for the latest video compression technique, H.264/AVC (Advanced Video Coding). CABAC typically provides a better high compression performance maximum 15% compared with CAVLC. However, the complexity of operation of CABAC is significantly higher than the CAVLC. Because of complicated data dependency during the encoding process, the complexity of operation is higher. Therefore, various architectures were proposed to reduce an amount of operation. However, they have still latency on account of complicated data dependency. The proposed architecture has two techniques to implement efficient pipeline architecture. The one is quick calculation of 7, 8th bits used to calculate a probability is the first step in Binary arithmetic coding. The other is one step reduced pipeline arcbitecture when the type of the encoded symbols is MPS. By adopting these two techniques, the required processing time was reduced about 27-29% compared with previous architectures. It is designed in a hardware description language and total logic gate count is 19K using 0.18um standard cell library.

• Journal of Broadcast Engineering
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• v.8 no.3
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• pp.259-267
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• 2003

In this paper, we propose a media processor to provide interactive services in mobile multimedia broadcasting environments. The proposed system Is designed to support various functionalities, such as generation of MPEG-4 IOD (Initial Object Descriptor)/OD(Object Descriptor)/BIFS (Binary Format for Scene) data, encapsulation of MPEG-4 AVC (Advanced Video Coding)/BSAC (Bit Sliced Arithmetic Coding) stream and generated IOD/OD/BIFS data into SL (Sync Layer) packet, packetization of SL packet into TS (Transport Stream) packet and multiplexing. The proposed media processor can provide MPEG-4 based interactive services for users.

• The Journal of the Acoustical Society of Korea
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• v.39 no.1
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• pp.38-46
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• 2020

LOw Frequency Analysis Recording (LOFAR) and Demodulation of Envelop Modulation On Noise (DEMON) grams are bearing-time-frequency plots of underwater acoustic signals, to visualize features for passive sonar. Those grams are characterized by tonal components, for which conventional data coding methods are not suitable. In this work, a novel LOFAR/DEMON gram compression algorithm based on binary map and prediction methods is proposed. We first generate a binary map, from which prediction for each frequency bin is determined, and then divide a frame into several macro blocks. For each macro block, we apply intra and inter prediction modes and compute residuals. Then, we perform the prediction of available bins in the binary map and quantize residuals for entropy coding. By transmitting the binary map and prediction modes, the decoder can reconstructs grams using the same process. Simulation results show that the proposed algorithm provides significantly better compression performance on LOFAR and DEMON grams than conventional data coding methods.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1987.04a
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• pp.31-34
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• 1987

A new efficientcoding system which can transmit video conferenceof viedeophone signals at a 64kbps is proposed. In addition to the interframe and CRC (Conditional Repleni shment Coding) system, BTVQ (Binary Tree searched Vector Quantizer)and RLC (Run Length Coding) methods are incorporated. Couble buffer memory is used for simple comtrol of channel symbol transmission and memory underflow And also buffer memory onerfolw is easily controlled by the thresholds of a MAD (Moving Area Betector)

• Journal of Communications and Networks
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• v.17 no.4
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• pp.328-338
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• 2015

Three areas of ongoing research in channel coding are surveyed, and recent developments are presented in each area: Spatially coupled low-density parity-check (LDPC) codes, nonbinary LDPC codes, and polar coding.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.9
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• pp.2131-2139
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• 2014

In this paper, a binary-coded physical-layer network coding (PNC) is considered when high-order modulation techniques are used at source nodes in wireless communication environments. In the conventional PNC schemes, tight power control and phase compensation are required at a relay node. However, they may not be feasible in practical wireless communication environments. Thus, we do not assume the pre-equalization in this paper, and we only utilize the channel state information at receiver (CSIR). We propose a signal detection method for the binary-coded PNC with high-order modulation, such as QPSK and 16QAM, at the source nodes, while the conventional scheme only consider the BPSK at source nodes. We also analyze the bit-error performance of the proposed technique in both uncoded and coded cases.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.1
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• pp.51-57
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• 2010

In this paper, It propose methods compressing BTC image utilizing data hiding technique. BTC is used to compress general digital image into binary image and applied into application such as printer. Additional information, transferred with binary image, is as big as the size of binary image. Therefore, we wish to reduce the total transmission bandwidth by decreasing the additional information with sustaining the small image degradation. Because typical BTC image doesn't have enough space for data hiding, we adopt Adaptive AMBTC (Absolute Moment BTC) algorithm to produce the binary image, and calculate virtual histogram from created binary image and modify this histogram for reducing the additional information. The proposed algorithm can reduce about 6-11 % of the image file size, compared with the existing BTC algorithm, without making perceptible image degradation.