• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3B
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• pp.557-564
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• 2000

This paper presents a watermarking algorithm for embedding visually recognizable pattern (Mark, Logo, Symbol, stamping or signature) into the image. first, the color image(RGB model)is transformed in YCbCr model and then the Y component is transformed into 3-level wavelet transform. Next, the values are assembled with pattern watermark. PN(pseudo noise) code at spread spectrum communication method and mutilevel watermark weights. This values are inserted into discrete wavelet domain. In our scheme, new calculating method is designed to calculate wavelet transform with integer value in considering the quantization error. and we used the color conversion with fixed-point arithmetic to be easy to make the hardware hereafter. Also, we made the new solution using mutilevel threshold to robust to common signal distortions and malicious attack, and to enhance quality of image in considering the human visual system. the experimental results showed that the proposed watermarking algorithm was superior to other similar water marking algorithm. We showed what it was robust to common signal processing and geometric transform such as brightness. contrast, filtering. scaling. JPEG lossy compression and geometric deformation.

• The KIPS Transactions:PartB
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• v.11B no.7 s.96
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• pp.813-820
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• 2004

This paper proposes a digital image watermarking which is robust to geometric distortions using an independent component analysis(ICA) of fixed-point(FP) algorithm based on secant method. The FP algorithm of secant method is applied for better performance in a separation time and rate, and ICA is applied to reject the prior knowledges for original image, key, and watermark such as locations and size, etc. The proposed method embeds the watermark into the spatial domain of original image The proposed watermarking technique has been applied to lena, key, and two watermarks(text and Gaussian noise) respectively. The simulation results show that the proposed method has higher speed and better rate for extracting the original images than the FP algorithm of Newton method. And the proposed method has a watermarking which is robust to geometric distortions such as resizing, rotation, and cropping. Especially, the watermark of images with Gaussian noise has better extraction performance than the watermark with text since Gaussian noise has lower correlation coefficient than the text to the original and key images. The watermarking of ICA doesn't require the prior knowledge for the original images.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.527-530
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• 2008

The watermarking method was suggested to protect the right of the copyright and the right of property, data loss is yes or not, copy prevention and pursuit about the brainchild(music, image, video and so on) in the early 1990. In this paper, we suggest the watermarking algorithm against the geometrical transformation of the medical images applied the Watershed algorithm. The robust watermarking methodology is being suggested using the several algorithm against the attacks such as compression, filtering, noise and geometrical transformation of the medical image.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.4
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• pp.630-637
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• 2003

This paper proposed a new watermarking algorithm using chaotic sequence instead of conventional M-sequence for protecting copyright to the author. Robustness and security is very important for watermarking process. We use multi-threshold value according to the human visual system for improving robustness of watermarking to each subband images coefficient differently after wavelet transform. And then, we embedded watermark image to original image by multi-watermark weights which are made by random sequence generator. We detect watermark image from the difference data which is made from each wavelet subband images. We also simulate the efficiency from the various possible attacks. Chaotic sequence is better than M-sequence, because the one is very easy to make sequence and the chaotic sequence is changed easy according to the initial value. So, the chaotic sequence has the better security than the conventional M-sequence.

• The Transactions of the Korea Information Processing Society
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• v.7 no.11
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• pp.3576-3583
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• 2000

Digital watermarks have recently been proposed for the purposes of copyright ptotechtion and autheutication for multimedia contents. A watermarking technique consists of an algorithm that incorporates a watermarking structure into an image in the spatial or frequency domains. In this paper we proposed a new watermarking method for authentication and integrity of digital images and the proposed algorithm uses the MD5 hash funiction and a symmetric key encryption algorithm. To decide the position of embedding watermark and the bit pasitionin the original image, the secret key is used as an input of the MD5 hash function. The simulation results show that the proposed algorithm has the advantage of difficulty to find positions of inserted watermarks, and keep the similar watermarked image quabty with Wong's method.

• Journal of Internet Computing and Services
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• v.11 no.2
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• pp.99-107
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• 2010

In this paper a blind watermarking algorithm for digital image is presented. The proposed method operates in wavelet domain. The watermark is decomposed into 2D-IMFs using BEMD which is the 2-dimensional extension of 1 dimensional empirical mode decomposition. The CDMA based on SS technique is applied to watermark embedding and detection process. In the watermark embedding process, each IMF of watermark is embedded into middle frequency subimages in wavelet domain, so subimages just include partial information about embedded watermark. By characteristics of BEMD, when the partial information of watermark is synthesized, the original watermark is reconstructed. The experimental results show that the proposed watermarking algorithm is imperceptible and moreover is robust against JPEG compression, common image processing distortions.

• Journal of the Korea Society of Computer and Information
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• v.7 no.2
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• pp.124-129
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• 2002

Currently, image processing are used widely and have various types of characteristics with the applications of VOD(Video on demand), the web casting services, the video conference systems and virtual realities. Using the scene change, at every time of video image transitions, an editor can classify the video context and also require a function of in(Boxing insertion. Digital watermarking provides a solution to illegal copying of digital contents and has many other useful applications, including web broadcast monitoring, transaction tracking, authentication, copy control and device control. The Purpose of this thesis is to implement of nonlinear moving picture editor for the multiple watermarking. For the effective watermarking performance, this thesis considers the protection of image quality reduction and robustness for hiding information concurrently.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.331-342
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• 2005

In this paper, we propose an efficient watermarking algorithm using block indexing. The proposed algorithm is a novel blind watermarking scheme using the indexed watermark value based on the spread spectrum method. The watermark insertion is allocated into index value of each block after dividing original image into sub-blocks. The watermark embedded in mappinged with index values of blocks, And the mappinged blocks convert to DCT and then the PN sequence embedded to middle frequency band. Consequently the watermark is expressed by index value of sub-blocks. The watermark extracted from the correlation of between PN sequence and watermarked image. Experimental results demonstrate that the watermarked image has a good quality in terms of imperceptibility and is robust against various attacks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.3
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• pp.489-497
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• 2009

Most of existent blind watermarking methods in frequency domain use coefficient relationship to detect the watermark without original image. But the change in coefficient values occurred when the original image was attacked by lossy JPEG compression or noise addition. So robustness of watermark detection was weaken. In order to solve these problems, this paper presents a robust watermarking method, which enables multiple watermark insertion. Also, in order to reduce errors in the detected value of watermarks according to small changes in the coefficient relationship when detecting watermarks, it set the change guard value for variation of the coefficients. The experimental results show that the proposed method has good image quality and is robust to various attacks such as the JPEG lossy compression, noise addition, etc.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.9
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• pp.1767-1778
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• 2009

A robust and secure InIm(Integral imaging)-based 3D watermarking scheme using cellular automata transform (CAI) is proposed. In the InIm-based 3D watermarking scheme, the elemental image array (EIA) watermark for the target watermark which has to be detected, is synthesized from the computational pickup process of InIm and embedded in a cover image. The EIA watermark can provide a robust reconstruction of the target watermark However, the 3D property of the EIA watermark causes a weakening of the security. To overcome this problem, the proposed method uses the CAT domain to embed and extract the EIA watermark in the cover image. The use of CAT significantly improves the security for our watermarking algorithm using a single secure key only. Experiments are presented to show that the proposed scheme shows robust and secure performances against various attacks.