• International Journal of Contents
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• v.11 no.3
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• pp.39-46
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• 2015

When host images are watermarked with CRT (Chinese Remainder Theorem), the watermark images are still robust in spite of the damage of the host images by maintaining the remainders in an unchanged state within some range of the changes that are incurred by the attacks. This advantage can also be attained by "zero-watermarking," which does not change the host images in any way. This paper proposes an improved zero-watermarking scheme for color images on the DCT (Discrete Cosine Transform) domain that is based on the CRT. In the scheme, RGB images are converted into YCbCr images, and one channel is used for the DCT transformation. A key is then computed from the DC and three low-frequency AC values of each DCT block using the CRT. The key finally becomes the watermark key after it is combined four times with a scrambled watermark image. When watermark images are extracted, each bit is determined by majority voting. This scheme shows that watermark images are robust against a number of common attacks such as sharpening, blurring, JPEG lossy compression, and cropping.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1487-1490
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• 2003

This paper shows the watermarking system that inserts copyright holder's logo in music file. In other words, a sound file is able to have an image information like a logo or letters. The watermarking system converts a sound file into an image file using spectrogram. In the spectrogram domain, a logo is inserted using spread spectrum. The proposed technique shows that the verification of copyright is better than the method using PN-Sequence.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.7
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• pp.487-494
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• 2013

Medical image watermarking has received extensive attention as wide security services in the healthcare information system. This paper proposes a blind medical image watermarking approach on the segmented gray-matter (GM) images by utilizing discrete wavelet transform (DWT) and discrete cosine transform (DCT) along with enhanced suppressed fuzzy C-means (EnSFCM) for the optimal selection of sub-blocks position to insert a watermark. Experimental results show that the proposed approach outperforms other methods in terms of peak signal to noise ratio (PSNR) and M-SVD. In addition, the proposed approach shows better robustness than other methods in normalized correlation (NC) values against several attacks, such as noise addition, filtering, JPEG compression, blurring, histogram equalization, and cropping.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1761-1784
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• 2017

In order to improve the embedding rate of reversible watermarking algorithm for digital image and enhance the imperceptibility of the watermarked image, an adaptive reversible image watermarking algorithm based on DE is proposed. By analyzing the traditional DE algorithm and the generalized DE algorithm, an improved difference expansion algorithm is proposed. Through the analysis of image texture features, the improved algorithm is used for embedding and extracting the watermark. At the same time, in order to improve the embedding capacity and visual quality, the improved algorithm is optimized in this paper. Simulation results show that the proposed algorithm can not only achieve the blind extraction, but also significantly heighten the embedded capacity and non-perception. Moreover, compared with similar algorithms, it is easy to implement, and the quality of the watermarked images is high.

• 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.

• Journal of Korea Multimedia Society
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• v.15 no.7
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• pp.837-846
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• 2012

This paper presents a watermarking scheme based on the perspective distance for the secure mash-up service. The proposed scheme embeds the watermark of the location information of satellite image and the user information using edge color histogram, which is dissimilar to general digital image. Therefore, this scheme can trace the illegal distributor and can protect private information of user through the watermarking scheme that is adaptive to satellite image. Experimental results verified that our scheme has the invisibility and also the robustness against geometric attacks of rotation and translation.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.7 no.2
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• pp.143-147
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• 2007

This paper proposes a new watermarking scheme in which a logo watermark is embedded into the discrete wavelet transform (DWT) domain of the original image using exact radial basis function neural networks (RBF). RBF will learn the characteristics of the image, and then watermark is embedded and extracted by the trained RBF. A watermark is added to the coefficients at the low frequency band of the DWT of an image and a watermark is embedded into the DWT domain using the trained RBF. The trained RBF also used in watermark extracting process. Experimental results show that the proposed method has good imperceptibility and high robustness to common image processing attacks.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.217-220
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• 2003

This paper presents a wavelet-based digital watermarking scheme for color images. We insert watermarks in the DWI domain using spread-spectrum correlation-based watermarking in luminance component of the color image. The watermark, two pseudorandom patterns, is inserted by modifying the wavelet coefficients at subband HL2, LH2, HH2 according to message bits. To detect watermark, we calculate the correlation between the watermarked image and pseudorandom patterns. As compared with correlations, the watermark detector determines embedding message. Experimental results show that the scheme is not only invisible but also robust to various attacks such as JPEG compression, noise addition and so on.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.7
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• pp.1488-1492
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• 2004

The digital signal has been replaced the analog signal in most of every field of multimedia including still image, animation, and audio due to the enormous extension of computer supply and the fast development of computer network. The consumers of information are able to enjoy the abundance of information because of one of the digital signal traits that very easy to regenerate the original data. Because of the trait, however, it is very hard for the producers of information to keep the copyright with the merit of original copy in quality excellency. In this paper, the watermarking technology which inserts a RGB color watermark in color image using the visual characteristics of wavelet coefficient was proposed. As a result, the PSNR value of image was varied depending on perceptual parameter, but we can obtain 32dB as a whole.

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.902-905
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• 2000

Because of the rapid growth of Internet and multimedia applications, how to protect IPR (intellectual property rights) has become a critical issue. Is one of the ways to overcome the problem of the protection of IPR. Digital watermarking call be applied to multimedia data, such as digital images, digital video, and digital audio. In this paper, we propose a digital watermarking technique for digital images to authenticate an owner or an image by embedding visually recognizable patterns, such as logos, signatures, or stamps into images In BDCT (block discrete cosine transform) frequency domain. The proposed method sorts the components of an original image twice. At the same time, the method, also, rearranges the components of a watermark twice in order to be more robust, and finally embeds the watermark into the image. From the experimental results, the conjunction of three similarity measurements shows that our proposed method is robust to image cropping, image filtering, and JPEG (the Joint Photographic Experts Group) both subjectively and objectively.