• Journal of Korea Multimedia Society
• /
• v.9 no.4
• /
• pp.505-514
• /
• 2006

We proposes a multipurpose image watermarking algorithm which embeds visible watermark and invisible watermark into an original image. This is to satisfy the two characteristics of copyright notification of the visible watermark and copyright protection of the invisible watermark. The visible watermark's transparency is highlighted to be easily identified in contrast to the original image and the invisible watermark is embedded in a spatial domain.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.4
• /
• pp.85-95
• /
• 1998

In this paper, a new watermarking method for a copy protectionof images is proposed. The proposed method adaptively embeds a watermark in the frequency domain of images using human visual system model. For this purpose, the Just Noticeable Differences(JNDs) of each frequency coeffeicient value of a luminance plane is first found using Watson and Solomon's visual system model. An invisible maximum watermark value with is different in every position according to the characteristics of images is determined usig JND and Minkowski metric. A low frequency domain is divided into two sets based on a PN-sequence to protect thewatermark from the attack. The watermarks are added to one set of coefficients and detecting a watermark, the difference between the mean values of absolute coefficient values of both sets is calculated. The embedded watermark is tested using statistical hypothesis based on test static dertermined by the ean difference. To demonstrate the perfromance of the proposed method, the new watermarking method is applied to a high frequency image and low frequency images. Experimenatal results show the watermark is invisible and robust to JPEGlossy compression and noise.

• Proceedings of the Korea Database Society Conference
• /
• 1999.06a
• /
• pp.519-523
• /
• 1999

본 연구는 디지털 이미지 데이터에 대한 창작자의 저작권 보호 기술인 watermarking 기술을 연구하였다. 저작권 보호를 위한 정보를 invisible watermark로 삽입하였고, watermarking된 칼라 이미지를 데이터 압축, Filtering, cropping 등과 같은 여러가지 외부 공격에 대한 내구성을 실험하였다. invisible watermark를 삽입하기 위하여 변형된 주파수 변환기법을 이용하였으며, 기존의 PRN(pseudo random number) 방법보다 가시성이 뛰어난 이미지 형태의 로고를 삽입하여 저작권에 대한 확증성을 제고하였다.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 1999.03a
• /
• pp.519-523
• /
• 1999

본 연구는 디지털 이미지 데이터에 대한 창작자의 저작권 보호 기술인 watermarking 기술을 연구하였다. 저작권 보호를 위한 정보를 invisible watermark로 삽입하였고, watermarking된 칼라 이미지를 데이터 압축, Filtering, cropping 등과 같은 여러 가지 외부 공격에 대한 내구성을 실험하였다. Invisible watermark를 삽입하기 위하여 변형된 주파수 변환기법을 이용하였으며, 기존의 PRN(pseudo random number)방법보다 가시성이 뛰어난 이미지 형태의 로고를 삽입하여 저작권에 대한 확증성을 제고하였다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.11C
• /
• pp.1118-1122
• /
• 2003

In this paper, we propose a new invisible digital watermarking scheme based on wavelet transform using singular value decomposition. Embedding process is started by decomposing the lowest frequency band image with 3${\times}$3 block among which we define the watermark block chosen by a key set; entropy and condition number of the block. A watermark is embedded in the singular values of each watermark blocks. This provides a robust watermarking in lowest possible time-frequency domain. To detect the watermark, we are locally modeling an attack as 3${\times}$3 matrices on the watermark blocks. Combining with the SVD and the attack matrices, we estimate watermark set corresponding to the watermark blocks. In each watermark block, we determine an optimal watermark which is justified by the T-testing. A numerical experiment shows that the proposed watermarking scheme efficiently detects the watermarks from several JPEG attacks.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1998.10a
• /
• pp.404-406
• /
• 1998

본 연구는 인터넷과 같은 가상공간에서의 칼라 영상 데이터에 대한 지적재산권 보호를 위한 Watermarking 기술을 연구하였다. 이미지에 Invisible Watermark를 삽입하였으며, 칼라 이미지를 압축, Filtering, truncation등과 같은 처리에도 Watermark의 내구성을 높이는 기술연구에 중점을 두었다.

• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10c
• /
• pp.565-567
• /
• 1998

본 연구는 인터넷과 같은 가상공간에서의 칼라 영상 데이터에 대한 지적재산권 보호를 위한 Watermarking 기술을 연구하였다. 이미지에 Invisible Watermark를 삽입하였으며, 칼라 이미지를 압축, Filtering, truncation등과 같은 처리에도 Watermark의 내구성을 높이는 기술 연구에 중점을 두었다.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.51 no.7
• /
• pp.302-307
• /
• 2002

Digital watermarking is the technique, which embeds an invisible signal including signal including owner identification and copy control information into multimedia data such as audio, video, and images for copyright protection. A new MPEG watermark embedding algorithm using complex block effect based on the Human Visual System(HVS) is introduced in this paper. In this algorithm, $8{\times}8$ dark blocks are selected, and the watermark is embedded in the DC component of the discrete cosine transform(DCT) by using quantization and modulus calculation. This algorithm uses a blind watermark retrieval technique, which detects the embedded watermark without using the original image. The experimental results show that the proposed watermark technique is robust against MPEG coding, bitrate changes, and various GOP(Group of Picture) changes.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.59 no.4
• /
• pp.390-394
• /
• 2010

This paper describes a study on developing an insert and detect system of digital watermark to the MPEG-2 coder and decoder. Digital watermark inserting system substitutes a coefficient among the DCT coefficients for new one. This replacement performs in MPEG-2 PS format. Watermark detecting system analyzes the input data stream of MPEG-2 and detect the probability of occurrence of a specific code or watermarking code. Our inserting system had very high invisibility and the PSNR of the results was 130 dB around. And our detection rate of watermark was over 99% in digital format and over 85% in analog captured format according to the quality of contents.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.4A
• /
• pp.336-344
• /
• 2002

Recently, aegis of authentication and creator'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 repeated through the entire image and adapted to the content of the image. It is 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. Watermark is inserted by utilizing Human Visual System (HVS) feature in the wavelet transformed frequency domain. Especially, watermark inserted into the high frequency concentrated textual area makes itself invisible.