• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.2
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• pp.883-900
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• 2017

In this paper block based blind secure gray image watermarking scheme based on discrete wavelet transform and singular value decomposition is proposed. In devising the proposed scheme, security is given high importance along with other two requirements: robustness and imperceptibility. The use of discrete wavelet transform not only improves robustness but the selection of bands with high tolerance towards noise caused an improvement in terms of imperceptibility. The robustness further improved due to the involvement of singular vectors along with singular values in watermark embedding and extraction process. Finally, to achieve security, the selected DWT band is decomposed into smaller blocks and random blocks are chosen for modification. Furthermore, the elements of left and right singular vectors of selected blocks are chosen based on their dependence upon each other for watermark embedding. Various experiments using different images as host and watermark were conducted to examine and validate the proposed technique. Additionally, the proposed technique is tested against various attacks like compression, affine transformation, cropping, translation, X shearing, scaling, Y shearing, filtering, blurring, different kinds of noises, histogram equalization, rotation, etc. Lastly, the proposed technique is compared with state-of-the-art watermarking techniques and their comparison shows significant improvement of proposed scheme over existing techniques.

• The KIPS Transactions:PartD
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• v.11D no.6
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• pp.1335-1340
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• 2004

This study introduces a technology utilizing digital images as electronic money by inserting watermark into the images. Watermarking technology assign contents ID to images and inserts the contents ID into the images in an unnoticeable way. The server that manages the issue and the usage of mage electronic money (called ‘WaterCash’ hereafter) stores issued contents ID to database and manage them as electronic money. WaterCash guarantees anonymity and prevents the forgery and modification of WaterCash based on semi-fragile watermarking technique. In addition, WaterCash is transferable and the illegal use of WaterCash can be prevented based on the watermarking technology. The watermarking .technology used in this paper was designed to be robust to image compression but vulnerable to intentional or non-intentional Image processing.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.1
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• pp.42-48
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• 2010

In this paper, we proposed analysis performance improvement technique for T-DMB watermarking based on MBOK spread spectrum. By applying the proposed scheme to T-DMB system, it allows additional data transmission and improves spectral efficiency of data transmission through watermarking spreading code. Using MBOK spread spectrum technique, data rate improved 2m-times existing direct sequence spread spectrum. However, since hardware complexity increase as the value of m becomes large, the method should be used with optimal situation. We analyze T-DMB watermarking techniques performance with MBOK spread spectrum and averaging. As a result, we confirm DER performance of MBOK spread spectrum scheme and it is shown system performance is improved as the number of averaging increases. The results of the paper can be applied to wireless multimedia digital broadcasting system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.203-208
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• 2019

Digital watermarking was developed to protect copyright by discouraging the illegal copying of digital content. On the other hand, recently, watermarking has also been used to verify the integrity of digital content, such as medical images, and detect illegal manipulation or distortion locations. Watermarking should be tenacious so as to protect copyright from illegal copying and should remain firm to the content through a range of attacks, such as distortion or filtering. At the same time, however, it should be removed easily even in a slight transformation of the material to verify the integrity. Therefore, this paper proposes a watermarking technique that easily checks and verifies the deformation or manipulation of digital images. In the proposed method, the entire image was examined in $16{\times}16$ blocks to check for deformation of the image. When deformation was detected, further inspection proceeded in $4{\times}4$ blocks and the location where deformation occurred was identified.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.6
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• pp.1409-1415
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• 2010

In this paper we proposed the watermarking technique using the markspace which is selected by tree-structure between the subbands in the wavelet domain and feature information in the spatial domain. The watermarking candidate region in the wavelet domain is obtained by the markspace selection algorithm divides the highest frequency subband to several segments and calculates theirs energy and the averages value of the total energy of the subband. Also the markspace of the spatial domain is obtained by the boundary information of a image. The final markspace is selected by the markspaces of the wavelet and spatial domain. The watermark is embedded into the selected markspace using the random addresses by LFSR. Finally the watermarking image is generated using the inverse wavelet transform. The proposed watermarking algorithm shows the robustness against the attacks such as JPEG, blurring, sharpening, and gaussian noise.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.521-524
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• 2004

Recently, acgis of authentication and crcator's copyright has become a matter of great concern by the diffusion of multimedia technique and the growth of the internet and the easily duplicated property of digital data. Consequently, many active researches have been made to protect copyright and to assure integrity by inserting watermark into the digital data. In this paper, watermark is repealed through the entire image and adapted to the content of the image. Achieved by an underlying process of transforming the digital image to the frequency domain by wavelet transform, which has three (vertical, horizontal, diagonal) directions and Multi-resolution features, and then choosing frequency area inferior to the human perceptibility and significant for invisible and robust watermark. We realize wavelet based image watermarking using Machine Vision of LabVIEW.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.2
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• pp.39-44
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• 2010

In this paper, we derive the channel capacity in order to transmit an additional data by using digital watermarking method in generalized-K fading channel. Spread spectrum watermarking is one of the digital watermarking methods which is the most promising technique due to it's very robustness to the channel noise and easy achieving of the signal detection by correlators at the receiver. It is important to analyze the channel capacity to transmit an additional data through wireless channel because the transmitted data would be affected by the channel fading effects. From the results, we confirm that the channel capacity of the SSW system can be determined by the HWR, WNR, PN length and host sampling frequency. Also, we verified that the level of HWR and WNR can be determined by the derived capacity formula. The results of this paper can be applied to general spread spectrum watermarking system.

• Spatial Information Research
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• v.13 no.4 s.35
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• pp.393-400
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• 2005

Due to the development of the network and Internet, it is easy to copy and spread digital data. These data has the advantage of being able to be copy without loss. However, this has generated a problem over copyright. The problem occurred in GIS, too. Although GIS data acquisition is the major cost there is insufficient effort made to protect copyright. For this reason watermarking could be a good method to guarantee owner's copyright. This paper will explain watermarking, and show an overview of watermarking studies connecting image and vector data.

• Journal of Internet Computing and Services
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• v.4 no.4
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• pp.27-34
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• 2003

Digital image manipulation software is now readily available on personal computers. It is therefore very simple to tamper with any image and make it available to others. Therefore. copyright protection of digital contents and insurance of digital image integrity become major issues. In this paper, we propose a hybrid watermarking method to identify locations of tampered region as well as copyright. Our proposed algorithms embed the PN-sequence into low frequency sub-band of the wavelet transform domain and it doesn't need the original image in extraction procedure. The experimental results show good robustness against any signal processing with tamper detection on still image.

• The Journal of the Korea Contents Association
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• v.6 no.7
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• pp.90-98
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• 2006

Digital watermarking is a technique embedding hidden information into multimedia data imperceptibly such as images and sounds. Generally an original image is transformed and coded watermark data is embedded in frequency domain watermarking models. In this paper, We propose a new color image watermarking technique using Fresnel transform. A watermark image is Fresnel - transformed and the intensity of transformed pattern is embedded into color image. In our watermarking model, an original image is converted from RGB components into YCrCb components and then the values of real number and imaginary number of a Fresnel-transformed pattern of a watermark image are embedded into Y component. The watermarking experiments were conducted to show the validity of the proposed method using PSNR value, and the results show that our method has the robustness against lossy compression like JPEG.