• Journal of Broadcast Engineering
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• v.10 no.2
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• pp.131-138
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• 2005

High-quality digital broadcasting contents are susceptible to illegal copy and unauthorized redistribution, which makes broadcasters difficult to protect valuable media assets. So, broadcasters and content providers need the technology for copyright protection of professional digital content. Digital watermarking technology is one of the most actively developed solutions for the copyright protection. This paper suggests the requirements of watermarking technology in DTV(Digital TV) environment for copyright protection and shows the developed real-time watermark embedding/detecting system for HD(High Definition)/SD(Standard Definition) video and experimental results of the system against watermark attack tests. Our watermarking system meets the watermarking requirements of invisibility, robustness and security of DTV environment.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.161-168
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• 2009

There are many research for efficient, robust and invisible watermarking system that protects the digital contents like a image and animation according to growth of IT industry. First of all, frequency domain watermarking system like DWT(Descrete Wavelet Transform) is excellent because of minimum loss of original image and robustness of external attack. But, if we raise the insertion strength of watermark, then blazing of image occurs on existing DWT watermarking system and we should have a regular square image. In this study, we research the overflow check for preventing image from blazing and a robust and invisible watermarking algorithm. And we research a free-size DWT watermarking system using padding bytes, without a dependency of size.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.87-90
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• 2002

A digital watermark is an invisible mark embedded in a digital image which used for copyright protection. In this paper, we propose a new optical watermarking system. A optical watermarking system is applied for digital watermarking by phase hologram and Mach-Zehnder interferometer. A optical watermarking technique to be hidden is phase modulated in a random patten, and its Fourier-transformed hologram image is superposed on a content image. The autentication information extract by using Mach-zehnder interferometer.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.227-230
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• 2002

A digital watermark is an invisible mark embedded in a digital image which used for copyright protection. In this paper, we propose a new optical watermarking system. A optical watermarking system is applied for digital watermarking by phase hologram and Mach-Zehnder interferometer. A optical watermarking technique to be hidden is phase modulated in a random patten, and its Fourier-transformed hologram image is superposed on a content image. The autentication information extract by using Mach-zehnder interferometer.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.51-59
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• 2009

A watermarking for copyright protection of digital contents for broadcasting have to be made for a real-time system. In this paper, we propose a real-time video watermarking system which is hardware-based watermarking system of SD/HD (standard definition/high definition) video with the STRATIX FPGA device from ALTERA. There was little visual artifact due to watermarking in subjective quality evaluation between the original video and the watermarked one in our experiment. Embedded watermark was extracted after robustness testscalled natural video attacks such as A/D (analog/digital) conversion. Our implemented watermarking hardware system can be useful in movie production and broadcasting companies that requires real-time contents protection systems.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.1
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• pp.13-20
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• 2013

A combined DWT and DCT based watermarking technique of low frequency watermarking with weighted correction is proposed. The DWT has excellent spatial localization, frequency spread and multi-resolution characteristics, which are similar to the theoretical models of the human visual system (HVS). The DCT based watermarking techniques offer compression while DWT based watermarking techniques offer scalability. These desirable properties are used in this combined watermarking technique. In the proposed method watermark bits are embedded in the low frequency band of each DCT block of selected DWT sub-band. The weighted correction is also used to improve the imperceptibility. The extracting procedure reverses the embedding operations without the reference of the original image. Compared with the similar approach by DCT based approach and DWT based approach, the experimental results show that the proposed algorithm apparently preserves superiori mage quality and robustness under various attacks such as JPEG compression, cropping, sharping, contrast adjustments and so on.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.6
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• pp.1019-1024
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• 2006

A system design and realization for real time DVR system with robust video watermarking algorithm for contents security is presented in this paper. The robust video watermarking is used the intraframe space region and interframe insertion simultaneously, and to be processed at real time on image data and algorithm is used the 64bits special purpose quad DSP processor with assembly and soft pipeline codes. The experimental result shows that the processing time takes about 2.5ms in the D1 image per frame for 60% moving image.

• Proceedings of the IEEK Conference
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• 2001.06d
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• pp.73-76
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• 2001

In this paper, we utilize a HVS(Human Visual System) watermarking method where watermarks are embedded in a DFT domain. The HVS watermarking method is robust for attacks like JPEC, filtering, noise, etc. But, when images are attacked by basic geometric attacks as cropping, scaling, rotation, a watermarks may not be detected. In this paper, we introduce the HVS watermarking method that inserts references In a domain of LSB(Least Significant Bit) of image. Experimental results show that the proposed method based on HVS watermarking method gives more robustness to the basic geometric attacks compared with original HVS watermarking methods.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 1999.03a
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• pp.519-523
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• 1999

본 연구는 디지털 이미지 데이터에 대한 창작자의 저작권 보호 기술인 watermarking 기술을 연구하였다. 저작권 보호를 위한 정보를 invisible watermark로 삽입하였고, watermarking된 칼라 이미지를 데이터 압축, Filtering, cropping 등과 같은 여러 가지 외부 공격에 대한 내구성을 실험하였다. Invisible watermark를 삽입하기 위하여 변형된 주파수 변환기법을 이용하였으며, 기존의 PRN(pseudo random number)방법보다 가시성이 뛰어난 이미지 형태의 로고를 삽입하여 저작권에 대한 확증성을 제고하였다.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.861-864
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• 2000

This paper aims to establish fundamentals of measuring and evaluating the performance of water-marking systems. We first present the general model of a watermarking method for still images. Based on this model, we propose a statistical method of measuring the performance and robustness of the watermarking system. Then, the DCT-based watermarking system is analyzed and its performance is evaluated by using the proposed method.