• Journal of Broadcast Engineering
• /
• v.7 no.4
• /
• pp.368-375
• /
• 2002

In this paper, we apply multiresolution wavelet transform for the digital image watermarking. For better result, we insert watermark into the images and set a proper weighting factor for each subband based on HVS model. With proposed algorithm, we confirm that the image quality is satisfactory and this method outperforms the previous methods against image compression and cropping.

• Proceedings of the IEEK Conference
• /
• 2002.06d
• /
• pp.121-124
• /
• 2002

This paper presents an adaptive digital image watermarking scheme that uses successive subband quantization (SSQ) and perceptual modeling. Our approach performs a multiwavelet transform to determine the local image properties optimal and the watermark embedding location. The multiwavelet used in this paper is the DGHM multiwavelet with approximation order 2 to reduce artifacts in the reconstructed image. A watermark is embedded into the perceptually significant coefficients (PSC) of the image in each subband. The PSCs in high frequency subbands are selected by setting the thresholds to one half of the largest coefficient in each subband. After the PSCs in each subband are selected, a perceptual model is combined with a stochastic approach based on the noise visibility function to produce the final watermark.

• Proceedings of the IEEK Conference
• /
• 2000.07b
• /
• pp.857-860
• /
• 2000

This paper presents a new watermarking method based on wavelet transform. Embedding algorithm call define robust area by varying thresholds and gives a watermark image the priority of significance by analyzing spatial correlation of the watermark image. Detector can adjust thresholds to the distorted watermarked image. Also detector can extract the embedded data without an original image. A new measurement for detecting the correct watermark is suggested. Simulation results show that the embedded watermark is robust against various signal processing and compression attacks.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.5
• /
• pp.1041-1046
• /
• 2009

In this paper, we proposed a robust watermark scheme for image based on SVD(Singular Value Transform) and Triplet. First, the original image is decomposed by using 3-level DWT, and then used the singular values changed for embedding and extracting of the watermark sequence in LL3 band. Since the matrix of singular values is not easily altered with various signal processing noises, the embedded watermark sequence has the ability to withstand various signal processing noise attacks. Nevertheless, this method does not guarantee geometric transformation(such as rotation, cropping, etc.) because the geometric transformation changes the matrix size. In this case, the watermark sequence cannot be extracted. To compensate for the above weaknesses, a method which uses the triplet for embedding a barcode image watermark in the middle of frequency band is proposed. In order to generate the barcode image watermark, the pattern of the watermark sequence embedded in a LL3 band is used. According to this method, the watermark information can be extracted from attacked images.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.11c
• /
• pp.1823-1826
• /
• 2003

본 논문에서는 디지털 영상의 인증 및 무결성을 위한 Fragile Watermarking 기법을 제안한다. 이 기법은 원 영상과 워터마크 영상을 각각 랜덤하게 섞고, 랜덤수와 LUT를 이용하여 워터마크를 LSB에 삽입하므로 보안성을 갖는다. 또한, 워터마크 삽입 추출과정에서 두 개의 비밀키와 XOR를 이용하여 간단히 처리할 수 있다. 실험을 통하여 영상의 변형 여부 및 조작 위치를 검출하였다.

• International Journal of Computer Science & Network Security
• /
• v.23 no.7
• /
• pp.141-148
• /
• 2023

During the medical data transmissions, the protection of the patient information is vital. Hence this work proposes a spatial domain watermarking algorithm that enhances the data payload (capacity) while maintaining the authentication and data hiding. The code is distributed at every pixel of the digital image and not only in the regions of non-interest pixels. But the image details are still preserved. The performance of the proposed algorithm is evaluated using several performance measures such as the mean square error (MSE), the mean absolute error (MAE), and the peak signal to noise Ratio (PSNR), the universal image quality index (UIQI) and the structural similarity index (SSIM).

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.6
• /
• pp.221-229
• /
• 2004

We present new digital watermarking scheme that embeds a watermark according to the characteristics of the image or video. The scheme is compatible with established image compression standard. We define a weighting function using a parent-child structure of the DCT coefficients in a block to embed a maximum watermark. The spatio-frequency localization of the DCT coefficients can be achieved with this structure. In the detection stage, we present an optimum a posteriori threshold with a given false detection error probability based on the statistical analysis. Simulation results show that the proposed algorithm is efficient and robust against various signal processing techniques. Especially, they are robust against widely used coding standards, such as JPEG and MPEG.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.8
• /
• pp.1663-1674
• /
• 2012

In this paper, we propose a new watermarking technique for copyright protection of stereo image. The proposed technique embeds watermark to the region which corresponds to occlusion of the disparity map to be extracted by the proposed stereo matching and the frequency coefficient with the appropriate value. We use discrete wavelet transform for frequency transform tool. The proposed algorithm consists of stereo matching, watermark rearrange, mark space selection, and watermark embedding/extracting. We tested the experiment about 4 stereo images which are from Middlebury site. We embedded the watermark to 4 stereo images and extracted it from the images after attacks. We also visually analyzed the watermark embedding images in 3D TV environment.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.43 no.4 s.310
• /
• pp.108-115
• /
• 2006

This paper presents a watermarking algorithm in the discrete wavelet transform domain using evolutionary algorithm. The proposed algorithm consists of wavelet-domain watermark insertion and genetic algorithm-based watermark extraction. More specifically watermark is inserted to the low-frequency region of wavelet transform domain, and watermark extraction is efficiently performed by using the evolutionary algorithm. The proposed watermarking algorithm is robust against various attacks such as JPEG and JPEG2000 image compression and geometric transformations.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.12C
• /
• pp.1214-1221
• /
• 2005

In this paper, we propose a digital watermarking method for still images, in which the human visual system (HVS) is used in the discrete cosine transform (DCT) domain. The modulation transfer function (MTF) of the HVS model is employed to increase the invisibility of the inserted watermark in images. The proposed watermarking method is shown to be robust to several common image processing techniques, including lowpass filtering and cropping. Also, using the energy relationship of the DCT, we derive the equation that directly computes the watermark weighting factor in the DCT domain for the specified peak signal to noise ratio (PSNR) of the still image and the length of watermark to be inserted. The difference between desired PSNR and PSNR in spatial domain is within 0.07dB for the 7 test images.