• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.9
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• pp.663-669
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• 2004

The mobile tole-cardiology system is the new research area that support an ubiquitous health care based on mobile telecommunication networks. Although there are many researches presenting the modeling concepts of a GSM-based mobile telemedical system, practical application needs to be considered both compression performance and error corruption in the mobile environment. This paper evaluates three wavelet ECG compression algorithms over CDMA networks. The three selected methods are Rajoub using EPE thresholding, Embedded Zerotree Wavelet(EZW) and Wavelet transform Higher Order Statistics Coding(WHOSC) with linear prediction. All methodologies protected more significant information using Forward Error Correction coding and measured not only compression performance in noise-free but also error robustness and delay profile in CDMA environment. In addition, from the field test we analyzed the PRD for movement speed and the features of CDMA 1X. The test results show that Rajoub has low robustness over high error attack and EZW contributes to more efficient exploitation in variable bandwidth and high error. WHOSC has high robustness in overall BER but loses performance about particular abnormal ECG.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.3
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• pp.55-62
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• 2012

EZW, also known as Embedded Zerotree Wavelet, is a technique that allows transforming original images into wavelet, then again compressing images using the transformed data. This algorithm demonstrates a simple structure and remarkable effectiveness. This paper has reformed the EZW to improve a compression efficiency. Fundamentally, EZW evaluates the priority level of wavelet-transformed data and stores them into four different categories considering the priority level of the data as well as their location information. The four categories are represented as the symbols P, N, Z, and T. Here, P and N correspond to the volume of data and the priority level whereas Z and T show the location information of data. Each letter is stored through the process of dominant pass. However, here is when the data of Z and T are stored redundantly which lead to unnecessary increase of data volume. In this paper, we propose a modified version of Embedded Zerotree Wavelet algorithm, which is designed to efficiently reduce the volume of redundantly stored data using four additionally inserted symbols. We name it EEZW, Extended Embedded Zerotree Wavelet. The proposed algorithm demonstrates the efficiency verified by a number of image and confirms an outstanding result through the PSNR(Peak Signal To Noise Rate) values, which measure their quality of images.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.3
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• pp.616-621
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• 2005

In this paper. digital watermarking algorithm based on human visual system and transform domain is presented. Firstly, original image is separated into RGB thannels, watermark is embedded into the coefficients of DCT so as to consider a contrast sensitivity and texture degrees. In preprocessing, DCT domain based transform is involved and binary image of visually recognizable patterns is utilized as a watermark. Consequently, experimental results showed that proposed algorithm is robust and imperceptibility such destruction attack as JPEG compression.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.4
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• pp.442-449
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• 2002

EZW (Embedded Zerotree Wavelet) is an efficient algorithm to encode wavelet-transformed image. In this algorithm, each coefficient of wavelet transformed image is given one of the specific symbols and encoded according to its significant priority. In this paper, we analysis the occurrence conditions of symbols in EZW and propose a modified EZW algorithm. In the proposed algorithm, the significance of an IZ (Isolated Zero) symbol is determined by the additional conditions as well as its absolute value. The occurrence of IZ symbols is decreased and the required bits for insignificant IZ symbols is saved, so we obtained good quality of the reconstructed image.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2C
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• pp.155-160
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• 2010

In this paper, we proposed a forensic mark algorithm which can embed the distributor's information at each distribution step to trace the illegal distribution path. For this purpose, the algorithm has to have the high capacity payload for embedding the copyright and user information at each step, and the embedded information at a step should not interfere with the information at other step. The proposed algorithm can trace the multilevel distribution because the forensic mark is generated by digital hologram and embedded in the DWT-SVD domain. For the high capacity embedding, the off-axis hologram is generated from the forensic mark and the hologram is embedded in the HL, LH, HH bands of the DWT to reduce the signal interference. The SVD which is applied the holographic signal enhanced the detection performance and the safety of the forensic mark algorithm. As the test results, this algorithm was able to embed 128bits information for the copyright and user information at each step. In this paper, we can embed total 384bits information for 3 steps and the algorithm is also robust to the JPEG compression.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.99-107
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• 2013

Controller area network (CAN) was designed for multiplexing communication between electronic control units (ECUs) in vehicles and thus for decreasing the overall wire harness. The increasing number of ECUs causes the CAN bus overloaded and consequently the error probability of data transmission increases. Since the time duration for the data transmission is proportional to CAN frame length, it is desirable to reduce the frame length. In this paper, a CAN message compression method is proposed using Data Length Code (DLC) and compression area selection algorithm to reduce the CAN frame length and the error probability during the transmission of CAN messages. By the proposed method, it is not needed to predict the maximum value of the difference in successive CAN messages as opposed to other compression methods. Also, by the use of DLC, we can determine whether the received CAN message has been compressed or not without using two ID's as in conventional methods. By simulations using actual CAN data, it is shown that the CAN transmission data is reduced up to 52 % by the proposed method, compared with conventional methods. By using an embedded test board, it is shown that 64bit EMS CAN data compression can be performed within 0.16ms and consequently the proposed algorithm can be used in automobile applications without any problem.

• Journal of Korea Multimedia Society
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• v.4 no.3
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• pp.247-256
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• 2001

Digital watermarking is a copyright protection technique for digital images which embed a code into the digital data so the data is marked. Watermarking techniques previously deal with on-line digital data and have been developed to withstand digital attacks such image processing, compression and geometric transformation. In this paper we propose a novel method of embedding watermarks in printed images. In the proposed algorithm, watermark is embedded in a dithered binary image by comparing the $2\times{2}$ blocks of the counting array is the number of 1 (WHITE) in the $16\times{16}$ blocks of the dithered binary image with predefined reference block pattern, which is generated by watermark values. The proposed algorithm is able to provide more information at a watermark because the proposed algorithm use both '1'and '0' as watermark values. The watermark information is detected by comparing the watermark which is reconstructed from the image which is embedded watermark with the original watermark which is embedded in a binary image. The performance of the proposed algorithm is compared with that of the conventional watermark embedding algorithm for printed images by detecting watermark for scan images.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1019-1022
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• 2002

The current paper proposes a wavelet-based digital watermarking algorithm using statistical characteristic of image and human visual system (HVS). The original image is decomposed into 4-level using a discrete wavelet transform (DWT), then the watermark is embedded into the perceptually significant coefficients (PSCs) of the image. In general, the baseband of a wavelet-decomposed image includes most of the energy of the original image, thereby having a crucial effect on the image quality. As such, to retain invisibility, the proposed algorithm does not utilize the baseband. Plus, the wavelet coefficients on the lowest level are also excluded in the watermark-embedding step, because these coefficients call be easily eliminated and modified by lossy compression and common signal processing. As such, the PSCs are selected from all subbands, except for the baseband and subbands on the lowest level. Finally, using the selected PSCs, the watermark is then embedded based on spatial masking of the wavelet coefficients so as to provide invisibility and robustness. Computer simulation results confirmed that the proposed watermarking algorithm was more invisible and robust than conventional algorithms.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.5
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• pp.365-370
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• 2003

In this paper, a new watermarking algorithm that based on wavelet packet transform is proposed for remote sensing images, which include many high frequency components. It applies watermark to the overall subband that includes the lowest frequency band. Watermark is embedded on original image after selecting the significant wavelet packet coefficients. For selection of significant coefficients which watermarks is embedded on, zerotree algorithm is applied to wavelet packet coefficients using CPSO (Coefficient Partitioning Scanning Order). From the experimental result, the proposed algorithm shows better invisibility and robustness performance compare with conventional watermarking methods. Especially, it demonstrates better robustness for high image compression in the remote images.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.2
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• pp.113-122
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• 2005

In this paper, we propose a multi-watermarking algorithm to satisfy two purposes: fragility against malicious attacks and robustness against non-malicious attacks. The algorithm can be used for image authentication using coefficients of Discrete Wavelet Transform(DWT). In the proposed method, watermarks are generated by combining binary image with some features extracted from the subband LL3, and then they are embedded into both the spatial and frequency domain. That is, on the spatial domain they are embedded into the Least Significant Bit(LSB) of all pixels of image blocks, and on the frequency domain the coefficients of the subband LH2 and HL2 are adjusted according to the watermarks. Thus the algorithm not only resists malicious attack but also permits non-malicious attacks such as blurring, sharpening, and JPEG compression.