Image Compression and Watermarking scheme using Scalar Quantization (original) (raw)
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We propose a robust quantization-based image watermarking scheme, called the gradient direction watermarking (GDWM).This is based on the uniform quantization of the direction of gradient vectors. In GDWM, the watermark bits are embedded by quantizing the angles of significant gradient vectors at multiple wavelet scales. The proposed scheme has the following advantages: 1)Increased invisibility of the embedded watermark because the watermark is embedded in significant gradient vectors, 2) robustness to amplitude scaling attacks because the watermark is embedded in the angles of the gradient vectors, and 3) increased watermarking capacity as the scheme uses multiple-scale embedding.. This watermarking technique is more Robust tovarious sizes of watermark Images.we construct a discrete-domain multiresolution and multidirectional expansion using non-separable filter banks, in much the same way that wavelets were derived from filter banks. This construction results in a flexible mutiresolution, local, and directional image expansion using contour segments, and thus it is named the contourlettransform. The discrete contourlet transform has a fast iterated filter bank algorithm that requires order N operations for N-pixel images. Finally, we show simulation results using contourlet denoising method over wavelet.
A NEW CONTOURLET TRANSFORM FEATURE TECHNIQUES FOR DIGITAL WATERMARKING
contourlet transform feature techniques for digital watermarking is proposed in this paper, now a day’s watermarking technique is powerful technique for security of copyright by hiding information, the input image is partitioned with different features are the combination of anisotropy and directionality using contourlet transform. In contourlet transform the image is decomposed with the help of laplacian pyramid and directional filter bank. In laplacian pyramid highest features are taken using low pass filter. After that given watermark image is inserted in low content part of the decomposed image. Band pass filter can be extract in noise image from the output image, based on contourlet transform can gives better PSNR and MSE as compared to existing techniques. Keywords- contourlet transform, watermark extraction .
Digital image watermarking based on angle quantization in discrete contourlet transform
Journal of King Saud University - Computer and Information Sciences, 2017
A robust and transparent watermarking scheme based on contourlet transform and quantization index modulation is proposed in this paper. In proposal algorithm, after taking contourlet, the coefficients are divided into three quadrants by using the symmetric property of the contourlet coefficients, then the angle coefficients are modulated for each of three points. The experimental results revealed that if the information of the image is utilized to determine the watermark and by using quantization index modulation properties, a higher robustness and more effective imperceptibility in proposed algorithm are achieved.
Digital Watermarking Based on Contourlet-SVD
In this paper, embedding a watermark image is performed in discrete Contourlet transform (CT) domain. It is known that the CT is able to capture the directional edges and contours superior to discrete wavelet transform. The proposed scheme is based on embedding watermark bits into the singular value of the selected blocks within low-pass sub-band of the original gray image CT. Two algorithms are implemented, the first uses adaptive quantization and the second uses quantization step. Our experimental results show that the method with quantization step has better fidelity in terms of peak signal to noise ratio (PSNR) and is more robust against geometrical and non-geometrical attacks in terms of normalized cross correlation (NC) in comparison with the first method, though, the method with adaptive quantization is blind in the sense not only quantization strategies but also, the original image is required.
Using Contourlet Transform and Discrete Cosine Transform and SVD for Digital Watermarking
In this paper, embedding a watermark in the image is performed in discrete Contourlet transform (CT) domain. It is known that the CT is able to capture the directional edges and contours superior to discrete wavelet transform. We introduce three methods. The first proposed method is based on embedding watermark bits into the singular value of the selected blocks within low-pass sub-band of the original gray image CT and uses adaptive quantization. The second method uses quantization step, are implemented. Our experimental results show that the second method with quantization step has better fidelity in terms of peak signal to noise ratio (PSNR) and is more robust against geometrical and nongeometrical attacks in terms of normalized cross correlation (NC) in comparison with the first method, though, the method with adaptive quantization is blind in the sense only quantization strategies but not the original image is required. The third proposed method is based on embedding watermark bits into the selected blocks within last sub-band of first level of the original gray image CT. This method is semi-blind and our experimental results show that robustness against geometrical and nongeometrical attacks in terms of normalized cross correlation (NC) is better than two previous methods and third method robust against too many attacks type.
Quantization-based Image Watermarking using multi-resolution wavelet decomposition
Watermarking techniques provide efficient methods for protecting copyright of intellectual property. Since the discrete wavelet transform allows independent processing of the resulting sub-bands without significant perceptible interaction between them, it is expected to make the watermark embedding more imperceptible. Furthermore, Wavelet-based watermarking techniques showed to be robust in the face of attacks. In this paper, we introduce an algorithm that applies a quantization step on the sorted detail coefficients of the L th level resolution of the wavelet decomposition of a true color image. The extraction process can be carried out blindly, i.e. without the need to refer to the original host image. Experimental results showed that the proposed embedding strategy causes low distortion on the watermarked images where the PSNR values were successfully greater than 40 dB. Furthermore, the proposed method showed effective resistance to attacks such as JPEG compression, image filtering, and Gaussian noise. More simulations were also carried out to evaluate the performance of the proposed algorithm in comparison to similar transformdomain techniques.
Application of contourlet transform and maximum entropy on digital image watermarking
2014
During the last few years, the copyright in multimedia world is becoming a real concern especially with the increase in transfer files, documents over networks. These data are actually very easy to hack: information becomes vulnerable to interception, copying, tampering or corruption. To meet this need, digital watermarking is a method of signal processing which inserted into a digital document an invisible watermark, containing a code robust against any attack that can affect the watermarked data. In this paper we presented a method of digital image watermarking based on contourlet transform and maximum entropy.
Enhancing robustness of digital image watermarks using Contourlet transform
2009 16th IEEE International Conference on Image Processing (ICIP), 2009
In this paper a simple and robust Contourlet-based image watermarking technique for copyright protection is presented. The main idea is to utilize the flexible representation of images provided by the Contourlet transform in designing a robust watermarking technique. The watermark is embedded into different bands to resist different kinds of signal processing attacks without causing visual artifacts into the host image. The performance of the technique is evaluated. The experimental results and comparisons with other Contourlet-based techniques prove the effectiveness of the proposed technique.
A Novel Robust Watermarking Technique Based on Nonsubsampled Contourlet Transform and SVD
The paper proposes a novel robust watermarking technique based on newly introduced Nonsubsampled contourlet transform(NSCT) and singular value decomposition(SVD) for multimedia copyright protection. The NSCT can give the asymptotic optimal representation of the edges and contours in image by virtue of the characteristics of good multi resolution shift invariance and multi directionality. After decomposing the host image into sub bands, we choose the low frequency directional sub band and apply singular value decomposition. The singular values of the original image are then modified by the singular values of nonsubsampled contourlet transformed visual grayscale logo watermark image. This hybrid approach improves the performance of the watermarking technique compared to earlier techniques. Experimental results shows that the hybrid technique is resilient to various linear and non linear filtering ,JPEG compression, JPEG2000 compression, Histogram equalization, Grayscale inversion, Con...
A highly robust two-stage Contourlet-based digital image watermarking method
Signal Processing: Image Communication, 2013
In this paper we propose a blind and highly robust watermarking method consisting of two embedding stages. In the first stage, the odd description of image is divided into nonoverlapped fixed size blocks and the signature (watermark) is embedded in the high frequency component of the Contourlet transform (CT) of the blocks. In the second stage, the signature is embedded in the low frequency component of the global CT of the image. The main issue associated with two-stage blind watermarking is the selection of the less affected signature among the two embedded signatures. In this paper a measure is introduced to decide between the two extracted signatures. Simulation results indicate that the proposed method achieves higher robustness compared to other known watermarking methods. Moreover, since watermark is embedded in the local as well as global CT coefficients of two different frequency bands, the proposed method is robust against a wide range of attacks. This is due to the fact that most of the attacks affect either a specific frequency band or a specific location in the watermarked image.