• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2000.11b
• /
• pp.161-166
• /
• 2000

본 논문에서는 영상 데이터의 저작권 보호를 위한 다중 워터마킹 기법을 제안한다. 다중 워터마킹은 하나의 컨텐츠에 복수개의 서로 다른 워터마크를 삽입하는 기법으로 각 워터마크들은 유일한 키로 정확한 추출이 가능해야 한다. 대역확산기법(spread spectrum)을 이용한 다중 워터마킹은 워터마크 삽입시 사용되는 키들간의 직교성(orthogonality)이 보장되어야 추출시 삽입된 워터마크들의 정확한 추출이 가능하게 된다. 따라서, 본 논문에서는 랜덤계열들을 Gram-schmidt 직교화 과정을 수행하여 직교화된 랜덤계열로 워터마크를 삽입하고 추출이 가능한 방법을 제안한다. 또한, 제안기법의 성능을 평가하기 위하여 가우시안 노이즈와 감마변환에 대하여 강인함을 보인다.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.13 no.6
• /
• pp.503-510
• /
• 2020

In this paper, we proposed an effective technique that greatly improves the security of the watermark by concealing the multiple-encrypted watermark in the LSB of the image pixel. Even if multiple encrypted watermark hidden in the LSBs of an image pixel are extracted, it is impossible to decrypt them, so the security of the watermark is maintained very high. If the watermark is multiple encrypted and hidden in the image using the proposed technique, the visual quality of the watermark-hidden image is very high, making it impossible to distinguish between the original image and the resulting image in which the watermark is hidden. The original watermark data can be completely extracted without loss, according to the procedure of the proposed technique, from the resulting image that the watermark is encrypted and hidden in the original image. The performance of the proposed technique was analyzed mathematically and the superiority of the proposed technique was confirmed through experiments. The proposed technique is an excellent image watermarking technique that greatly improves the security of the watermark hidden in the image compared to the existing technique.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.10a
• /
• pp.157-160
• /
• 2000

다중 워터마킹은 하나의 컨텐츠에 2개 이상의 다른 워터마크를 삽입하는 것으로 각 워터마크는 유일한 키로 정확하게 추출할 수 있어야 한다. 대역확산법(spread spectrum)을 이용한 다중 워터마킹은 삽입되는 워터마크간의 직교성(orthogonality)이 제공되어야 삽입된 워터마크들의 정확한 추출이 가능하다. 랜덤계열과 Hadamard 계열을 이용한 기존의 방법은 직교성이 보장되지 않기 때문에 워터마크가 정확히 추출되지 않은 문제가 발생한다. 따라서, 본 논문에서는 랜덤계열들을 Gram-schmidt 직교화 과정을 이용하여 직교화시킨 후, 직교화 된 랜덤계열로 워터마크를 삽입하여 정확한 추출이 가능한 방법을 제안하였다.

• The KIPS Transactions:PartC
• /
• v.8C no.6
• /
• pp.703-710
• /
• 2001

In this paper, we consider a multiple watermarking for image copyright protection. Multiple watermarking can be defined that two or more watermarks are inserted into the same content. Multiple watermarking using spread spectrum technique is able to extract the correct watermarks from the watermarked content when the orthogonality among keys should be guaranteed only. To keep the orthogonal property between keys, we perform the process of Gram-Schmidt on the random sequences. The orthogonalized sequences are used as keys to embed the watermarks. The proposed method can not only extract correctly the embedded watermarks but also show the robustness against various attacks such as Gaussian noise addition, histogram equalization, gamma correlation, sharpening and brightness/contrast adjustment.

• The KIPS Transactions:PartB
• /
• v.14B no.5
• /
• pp.337-342
• /
• 2007

Multi-level has advantage to express image in all levels with different images. This paper proposes digital watermarking built-in technique to transform color image to YCbCr color space to guarantee robustness and imperceptibility of the watermark in the various expression of color images, and to hide multi-level data which shows spread spectrum from low resolution to whole resolution for the Y-signal of multi-level. In color signal, Y-signal and low resolution built-in watermark has risk to be visible, but it can guarantee the robustness of watermark in various colors and transformed images. As a result of the experiment, wavelet compression image with built-in watermark showed robustness and imperceptibility of watermark.

• The Journal of the Acoustical Society of Korea
• /
• v.32 no.1
• /
• pp.71-78
• /
• 2013

This paper describes a multiple audio watermarking using Quantization Index Modulation (QIM) on frequency phase and magnitude response. Proposed embedding procedure is composed of two stage. At the first stage, the watermark is embedded on the frequency phase response using QIM. In the second stage, the watermark is embedded using adaptive QIM with the step-size that is adaptively determined using the maximum value of the frequency magnitude response of every frame. The watermark is extracted by calculating the Euclidean distance as the blind detection. The proposed method is robust against most of attacks of audio watermark benchmarking. For the Fourier attacks, the proposed method shows over 95% recovery rate.

• The KIPS Transactions:PartB
• /
• v.12B no.3 s.99
• /
• pp.291-300
• /
• 2005

We are required to adequately adjust the distributed contents to each device and users' demands on the network and to obtain authentication of ownership for our information to prevent the illegal usage of our digital information by non-owners. In this paper, we propose scalable digital watermarking of contents within a compression domain based on Orthogonal Forward Wavelet Transforms, and the proposed method focuses on robust watermark algorithms that are not visually recognizable to embedded ownership information. Therefore, it proposes a watermark insertion methods based on spread spectrum techniques and Provides a watermark key. As a result, it not only extracted the contained watermark from the intentionally altered images, but also secured the watermark information extraction from partial images and ensure the decrease of BER (Bit Error Rate) in the images containing watermarks even when more watermark inserted images are transmitted.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.11
• /
• pp.1946-1953
• /
• 2006

Because the embedded watermark of luminance component guarantees the extraction of ownership information when the color image is converted to gray scale image, the information of ownership right as to the luminance component is embedded in the luminance-chrominance color space such as YCbCr. Therefore, this paper proposes watermark embedding, extraction and authentication algorithm of color image. which considers the device and performance of multimedia contents service by focusing on the robustness and invisibility of watermark. The color image is converted from RGB color space to YCbCr color space, and then the properties of each component of Y(Luminance), Cb(Color Differences) and Cr(Color Differences) are considered in order to embed, extract and certify multi-level watermark in the frequency domain based on the wavelet. As a result, it can guaranteed the robustness for the JPEG compression and invisibility of watermark for multi-level.

• Proceedings of the KIEE Conference
• /
• 2007.10a
• /
• pp.167-168
• /
• 2007

본 논문에서는 얼굴, 지문 등의 생체특징을 안전하게 은닉하고 효과적으로 은닉정보를 추출할 수 있는 웨이블렛 기반 워터마킹 기법을 제안한다. 제안된 방법은 웨이블렛을 이용하여 워터마크 삽입위치를 결정하고 웨이블렛 변환된 영상과 배경영상간의 차와 삽입위치 주변의 영상에 분산값을 이용해 퍼지 함수를 이용하여 적응적 가중치 값을 결정한다. 은닉된 워터마크 데이터는 워터마크가 삽입된 영상에 웨이블렛 변환을 적용하여 효과적으로 생체특징을 추출한다. 제안된 방법의 타당성을 검증하기 위하여 워터마크 데이터인 생체특징의 은닉 전과 후의 특성분석과 워터마크 알고리즘이 생체 인식시스템에 미치는 영향을 평가하였다. 실험한 결과 제안된 방법은 효과적으로 생체정보를 은닉하고 생체인식률의 저하 없이 효과적으로 생체정보를 보호할 수 있음을 확인 할 수 있었다.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.36S no.12
• /
• pp.27-33
• /
• 1999

A wavelet based multiresolution watermarking method using the human visual system (HVS) is proposed, in which a different number of watermarks, in proportion to the energy contained in each band, are embedded into each band. Experiments with various test images show that the proposed three-level wavelet based method is robust to various attacks such as joint photographic experts group (JPEG) compression, smoothing, cropping, collusion, multiple watermarking, and so on.