• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1267-1274
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• 2007

In this paper, we propose a digital watermarking algorithm for digital hologram generated by computer generated hologram(CGH) method. Digital hologram generated by a computer calculation(CGH) is one of the most expensive contents and its usage is being expanded. Thus, it is highly necessary to protect the ownership of digital hologram. In this paper two digital watermarking schemes are introduced hologram-domain and global 2DDCT-domain scheme. Proposed watermarking scheme showed very high imperceptibility and quite high robustness against the attacks. The purpose of this paper is to introduce these global 2DDCT based watermarking schemes. Thus, we expect that these and the contents in this paper can be very useful bases for the further digital watermarking schemes of the digital holograms.

• 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.

• Journal of Korea Multimedia Society
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• v.10 no.1
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• pp.36-48
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• 2007

This paper proposed 3D keyframe animation using orientation interpolator. 3D keyframe animation consists of a number of transform nodes that have geometrical node of initial model and several interpolator nodes that represent the object moving. In the proposed algorithm, we randomly selects transform nodes with orientation interpolator node and performs to resample quaternion components for haying uniform key time. And then, watermark bits are embedded into quaternion components with large rotation angles. Experimental results verified that the watermark embedded by the proposed algorithm had good robustness against geometrical attacks and timeline attacks and also PSNR of keyvalue in orientation interpolator node is above 42dB.

• Journal of the Korea Society of Computer and Information
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• v.15 no.2
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• pp.109-117
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• 2010

Digital watermarking has drawn extensive attention for protecting digital contents from unauthorized copying. This paper proposes a new watermarking scheme in frequency domain for copyright protection of digital audio. In our proposed watermarking system, the original audio is segmented into non-overlapping frames. Watermarks are then embedded into the selected prominent peaks in the magnitude spectrum of each frame. Watermarks are extracted by performing the inverse operation of watermark embedding process. Simulation results indicate that the proposed scheme is robust against various kinds of attacks such as noise addition, cropping, resampling, re-quantization, MP3 compression, and low pass filtering. Our proposed watermarking system outperforms Cox's method in terms of imperceptibility, while keeping comparable robustness with the Cox's method. Our proposed system achieves SNR (signal-to-noise ratio) values ranging from 20 dB to 28 dB. This is in contrast to Cox's method which achieves SNR values ranging from only 14 dB to 23 dB.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1751-1758
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• 2008

Digital holography interference pattern generated by a computer calculation (CGH) is one of the most expensive contents and its usage is being expanded. Thus, it is highly necessary to protect the ownership of digital hologram. In this paper a hologram-domain and a frequency-domain electronic watermarking schemes were proposed. The hologram-domain scheme was only to compare the results to the ones from frequency-domain scheme and the frequence-domain scheme used 2-dimensional against the attaks. Especially the MDWT-domain scheme was very high robustness such that th error ratio at the worst case was only 3%. Thus, we expect that it is used as a good watermarking scheme of digital hologram with high performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.788-799
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• 2007

This paper presents a watermarking method for copyright protection and illegal copy prevention of mobile 3D contents. The proposed method embeds copyright information and user's phone number into spatial domain and encryption domain of mobile animation data based on Buyer-Seller watermarking protocol. Furthermore, we insert user's operation key so that only authorized user can play 3D animation game in mobile device. We implemented the proposed method by using mobile animation tool, G3-SDK. From experimental results, we verified that the proposed method is capable of copyright protection and illegal copy prevention since the watermark can be well extracted against geometrical attacks, such as noise addition, data accuracy variableness and data up/down scaling.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.6
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• pp.41-50
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• 2003

For copyright protection of digital contents, we employ watermarking techniques to embed watermark signals into digital host data. In this paper we propose an adaptive watermarking algorithm for three-dimensional (3-D) mesh models. Watermark signals are inserted into vertex coordinates adaptively according to changes of their position values. While we embed strong watermarks in the areas of large variations, watermarks are weakly inserted in other areas. After we generate triangle strips by traversing the 3-D model and convert the Cartesian coordinates to the spherical coordinate system, we calculate variations of vertex positions along the traversed strips. Then, we insert watermark signals into the vertex coordinates adaptively according to the calculated variations. We demonstrate that imperceptibility of the inserted watermark is significantly improved and show the bit error rate (BER) for robustness.

• Journal of Broadcast Engineering
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• v.9 no.1
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• pp.64-73
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• 2004

A robust watermarking algorithm is proposed for 3D mesh models. Watermark is inserted into the 2D image which is extracted from the target 3D model. Each Pixel value of the extracted 2D image represents a distance from the predefined reference points to the face of the given 3D model. This extracted image is defined as “range image” in this paper. Watermark is embedded into the range image. Then, watermarked 3D mesh is obtained by modifying vertices using the watermarked range Image. In extraction procedure, the original model is needed. After registration between the original and the watermarked models, two range images are extracted from each 3D model. From these images. embedded watermark is extracted. Experimental results show that the proposed algorithm is robust against the attacks such as rotation, translation, uniform scaling, mesh simplification, AWGN and quantization of vertex coordinates.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.3
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• pp.155-162
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• 2008

In this paper we proposed a video watermarking algorithm based on a three dimension discrete wavelet transform (3D DWT) and direct spread spectrum (DSS). In the proposed method, the information watermark is embedded into followed frames, after sync watermark is embedded into the first frame. Input frames are divided into sub frames which are located odd row and even row. The sub frames are arranged as 3D frames, and transformed into 3D wavelet domain. In this domain the watermark is embedded using DSS. Existing video watermarking using 3D DWT is non-blind method but, proposed algorithm uses blind method. The experimental results show that the proposed algorithm is robust against frame cropping, noise addition, compression, etc. acquiring BER of 10% or below and sustains level of 40dB or above on the average.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11A
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• pp.870-881
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• 2009

The rapid development of healthcare information management for 3D medical digital library, 3D PACS and 3D medical diagnosis has addressed security issues with medical IT technology. This paper presents multiple 3D medical image data for protection, authentication, indexing and diagnosis information hiding applied to healthcare information management. The proposed scheme based on POCS watermarking embeds the robust watermark for doctor's digital signature and information retrieval indexing key to the distribution of vertex curvedness and embeds the fragile watermark for diagnosis information and authentication reference message to the distance difference of vertex. The multiple embedding process designs three convex sets for robustness, fragileness and invisibility and projects 3D medical image data onto three convex sets alternatively and iteratively. Experimental results confirmed that the proposed scheme has the robustness and fragileness to various 3D geometric and mesh modifiers at once.