• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.6
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• pp.74-79
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• 2008

In this paper, we propose and design a new 0.264/AVC watermarking algorithm for protection of copyright by inserting a watermark after quantization. This invisible watermarking algorithm insets a watermark into chrominance components of I frame such that we can avoid degradation of original images. According to test results we could limit image degradation by 1dB, avoid bit rate increment within 2% and increase processing time by only 2%. The IP is designed by Hynix 0.25 micron technology and the maximum operating frequency of 115MHz is achieved. The PSNR of the embedded watermark is about 35dB according to the test result.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.568-570
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• 1998

본 연구는 Wavelet Transform을 이미지 처리에 적용하여 지적재산권 보호를 위한 Watermarking 기술을 연구하였다. Watermark가 이미지에 Invisible하게 삽입되면서 압축, Filtering, truncation등과 같은 이미지 처리에도 강력한 Watermark 기술 연구에 중점을 두었다. 특히 완벽한 복원을 위하여 Wavelet Transform을 사용하였고, 또한 DCT기술을 접목시킴으로 해서 압축에 강력한 결과를 나타내게 되었다.

• Journal of Korea Multimedia Society
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• v.8 no.12
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• pp.1572-1580
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• 2005

The common requirements for watermarking are usually invisibility, robustness, and capacity. We proposed the watermarking for 3D mesh model based on projection onto convex sets for invisibility and robustness among requirements. As such, a 3D mesh model is projected alternatively onto two convex sets until it converge a point. The robustness convex set is designed to be able to embed watermark into the distance distribution of vertices. The invisibility convex set is designed for the watermark to be invisible based on the limit range of vertex movement. The watermark can be extracted using the decision values and index that the watermark was embedded with. Experimental results verify that the watermarked mesh model has both robustness against mesh simplification, cropping, affine transformations, and vertex randomization and invisibility.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.97-100
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• 2002

In this paper, we propose a watermarking technique that embeds a digital watermark into digital images for the proof of owner or copyright protection. Proposed algorithm is based on discrete wavelet transform. Zerotree structure defined by Shapiro's embedded zerotree wavelet(EZW) algorithm is used. In the proposed algorithm, a digital watermark is embedded on only significant wavelet coefficients chosen by QSWT for the robustness of the algorithm. In other words, only the values of significant wavelet coefficients are modified in accordance with the given watermark pattern. We use the relationship among neighboring coefficients when modifying chosen coefficients to keep good image quality. Visual recognizable patterns such as binary images are used as a watermark. The experimental results show that the proposed algorithm has robustness under a variety of attacks such as JPEG compression, sharpening and blurring and also show that it has a better performance in PSNR comparing with other algorithms.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2427-2429
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• 1998

Digital watermarking is the techinque which embeds the invisible signal into multimedia data such as audio, video, images, for copyright protection, including owner identification and copy control information. This paper proposes a new watermark embedding and extraction technique by extending the direct sequence spread spectrum technique. The proposed technique approximates the frequency component of pixels in spatial domain by using Laplacian mask and adaptively embeds the watermark considering the HVS to reduce the degradation of Image. In watermark extraction process, the proposed technique strengthens the high frequency components of image and extracts the watermark by demodulation. All this processes are performed in spatial domain to reduce the processing time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.2
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• pp.1-8
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• 2008

The object of watermarking is to prevent from copying and distributing without the copyright or right of ownership. In case of using watermark as an image data we can detect watermark whether an original image exists or not. In this paper, we proposed that an image data is used for watermark and the watermark is detected without an original image. After the original image is transformed with DWT and the watermark is transformed with DCT, they are transformed with binary number. We calculate an optimal bit position for concealing watermark of an original binary image and insert the watermark and determine the best position for robustness against JPEG compression, filtering, and resampling attacks within inserted watermark image. In this paper, we are able to confirm the right of copyright and ownership easily while using invisible watermark and also we can detect a watermark without an original image.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.3
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• pp.108-111
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• 2002

This paper proposes an new water mark embedding and extraction technique which extends the direct sequence spread spectrum technique. The proposed technique approximates the complexity of image and block in spatial domain using Laplacian filtering and watermark is adaptively embedded in the mid-frequency DCT components. Local parity bits are attached to higher-frequency DCT components and they are used to detect extraction errors and correct those errors. In extraction process the proposed method boosts the higher frequency components of image and extracts the watermark by demodulation and this information is verified and adjusted by parity bits. Experimental results show it is invisible and robust to several external 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.

• 전자공학회논문지 IE
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• v.43 no.4
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• pp.37-42
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• 2006

This paper proposes a adaptive video watermarking algorithm according to bitrate and motion vector size in MPEG2 system. The watermark strength in the I-frames is adapted for quantization step size and the strength in the P-B-frames is adapted for quantization step size and motion vector of macroblock to make the watermark more robust against the accompanying degradation due to aggressively compression. A realtime watermark extraction is done directly in the DCT domain during MPEG decoding without full decoding of MPEG video. The experimental simulations show that the video quality results almost invisible difference between the watermarked frames and the original frames and the watermark is resistant to frame dropping, MPEG compression, GoP conversion and low pass filter attacks.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.6A
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• pp.602-609
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• 2002

In this paper, we propose an robust invisible watermarking method using wavelet transform and singular value decomposition for the ownership protection. of images. For this method, after we decompose the original image in three level using wavelet transform, we use singular value decomposition based key depended watermark insertion method in the lowest band $LL_3.$ And we also watermark using DCT for extraction of watermark and verification of robustness. In the experiments, we found that it had a good quality and robustness in attack such as compression, image processing, geometric transformation and noises. Especially, we know that this method have very high extraction ratio against nose and JPEG compression. And Digimarc's method can not extract watermark in 80 percent compression ratio of JPEG, but the proposed method can extract well.