Embedding Watermark Bits Research Articles

Multilevel histogram shape‐based image watermarking invariant to geometric attacks

AbstractIn this paper, a geometrically invariant image watermarking scheme is proposed by exploiting multilevel histogram shapes. The embedding procedure starts by decomposing the host image with the first level Haar wavelet. After that, histograms are extracted from the approximation subband via several rounds, which are used to embed watermark bits. Each round of embedding first extracts a histogram at a specified level. Then the histogram is split into fragments, into which a number of watermark bits can be embedded. In this way, a considerable watermarking capacity is available. Besides, a histogram adjustment in the first embedding round is suggested to guarantee good population of histogram bins. Experimental results support its robustness against various common attacks and geometric attacks. Moreover, the scheme can embed multiple watermark sequences with various robustness and capacity profiles, which enriches its practical applications.

SSVS-SSVD Based Desynchronization Attacks Resilient Watermarking Method for Stereo Signals

Most of the audio signals in real-world applications are stereo signals. However, the previous desynchronization attacks resilient watermarking methods cannot preserve perceptual quality or achieve robustness when constrained by high embedding rates and stereo host. In this paper, based on two novel features segmental singular values summation (SSVS) and segmental singular values difference (SSVD) that are generated using discrete cosine transform (DCT) and singular value decomposition (SVD), we present a robust watermarking method for stereo signals that not only is robust to desynchronization attacks and common signal processing attacks but also has a larger embedding rate compared with the previous methods. In the proposed method, we first apply DCT and SVD on each segment of the host signal to extract the SSVS feature and the SSVD feature. Then we generate the adaptive embedding parameters and embed watermark bits via optimized embedding strategies based on these features. Due to the use of the adaptive embedding parameters and the optimized embedding strategies, the proposed method significantly increases the embedding rate without compromising the robustness and perceptual quality. Analysis results show our proposed method outperforms the state-of-the-art methods by a large margin, where the perceptual quality improvement is over 14%, and the robustness against desynchronization attacks is improved by more than 49% when the embedding rate is 70 bps.

A secure gray-scale image watermarking technique in fractional DCT domain using zig-zag scrambling

Security of watermark is a huge concern when dealing with imperceptible watermarking for copyright protection and owner identification. A novel watermarking technique that is intrinsically secure against unauthorized extraction of watermark and robust against a variety of attacks has been proposed in this paper. Semi-blind in nature, the technique employs fractional discrete cosine transform (FDCT) and zig-zag scrambling to add a layer of security while embedding watermark bits in the cover image. Transformation through multiple fractional value pairs yields robust results against attacks for every cover image. A pair out of these is chosen while embedding the watermark. The same pair is needed at the time of extraction of original watermark from a signed image. This pair of unique values adds a layer of security in the proposed technique. After dividing the cover image into sub-blocks that are non-overlapping, fuzzy entropy is used to make the selection of appropriate sub-blocks in which watermark bits are to be embedded. These blocks are first mapped in a zig-zag fashion and then, after selection of half sub-blocks, FDCT is applied on each of them. FDCT coefficients serve as training data for Kernel extreme learning machine (KELM). Used as a non-linear regression model, KELM predicts the value of a particular coefficient with the help of neighboring transform domain coefficients. Multiple scaling factors are used to control the extent to which the watermark bit modifies the predicted coefficient. Strength of these scaling factors is determined and controlled with the help of standard deviation of every selected sub-block. The technique shows perfect extraction of watermarks (Normalized correlation=1.0, Bit error ratio=0.0) against attacks like median filtering (3 × 3), Gaussian filtering, Weiner filtering, JPEG compression (Quality factor 40) and gamma correction. Even for other attacks, the extracted watermarks are not too bad in quality that they are beyond recognition.

Optimal Colour Image Watermarking Using Neural Networks and Multiobjective Memetic Optimization

This paper deals with the problem of robust and perceptual logo watermarking for colour images. In particular, we investigate trade-off factors in designing efficient watermarking techniques to maximize the quality of watermarked images and the robustness of watermark. With the fixed size of a logo watermark, there is a conflict between these two objectives, thus a multiobjective optimization problem is introduced. We propose to use a hybrid between general regression neural networks (GRNNs) and multiobjective memetic algorithms (MOMA) to solve this challenging problem. Specifically, a GRNN is used for efficient watermark embedding and extraction in the wavelet domain. Optimal watermark embedding factors and the smooth parameter of the GRNN are searched by a MOMA for optimally embedding watermark bits into wavelet coefficients. The experimental results show that the proposed approach achieves robustness and imperceptibility in watermarking.

Copyright protection method of big data based on nash equilibrium and constraint optimization

Data watermarking technology is an effective means to protect the copyright of big data. In order to embed robust and highly available data watermarks, firstly, based on the game theory, a Nash equilibrium model between watermark robustness and data quality is established to solve the optimal number of data group. Then, the mapping relationship between data group and watermark bit is established by using secure hash algorithm.Finally, under the constraint of data usability, the improved particle swarm optimization algorithm is used to solve the optimal solution of data change for each data group, and then the data is changed accordingly to complete the embedding of watermark bit. In order to verify the copyright ownership of big data, the corresponding watermark extraction method is also given in this paper. Watermark extraction is the inverse process of watermark embedding. First, it traverses all the groups and extracts the bits that might be embedded in each group. Then, the actual embedded watermark bit is finally determined by most election strategies. The experimental results show that the proposed method can not only detect watermarks under different attack conditions, ensure the robustness of big data watermarks, but also achieve better data quality, and the comprehensive effect of data watermarks is better than the existing methods.

An Optimized Digital Watermarking Scheme Based on Invariant DC Coefficients in Spatial Domain

Digital watermarking has become an essential and important tool for copyright protection, authentication, and security of multimedia contents. It is the process of embedding a watermark in the multimedia content and its extraction. Block-based discrete cosine transform (DCT) is a widely used method in digital watermarking. This paper proposes a novel blind image watermarking scheme developed in the spatial domain by quantization of invariant direct current (DC) coefficients. The cover image is redistributed and divided into non-overlapped square blocks and then the DC coefficients invariant to rotation, row and column flip operations, without utilization of the DCT transform, are directly calculated in the spatial domain. Utilizing the quantization parameter and watermark information, the modified DC coefficients and the difference between DC and modified DC coefficients are calculated to directly modify the pixel values to embed watermark bits in the spatial domain instead of the DCT domain. Optimal values of the quantization parameter, which plays a significant role in controlling the tradeoff between robustness and invisibility, are calculated through differential evolution (DE), the optimization algorithm. Experimental results, compared with the latest similar schemes, demonstrate the advantages of the proposed scheme.

An image watermarking method based on visual saliency and contourlet transform

For the purpose of enhancing the imperceptibility and the robustness of watermark, a new image watermarking method based on visual saliency and contourlet transform is proposed. In this algorithm, salient object detection and contourlet transform are operated separately on host image. After dividing the transformed low-pass sub-band into nonoverlapping blocks, the saliency values and the energy distribution of the block determine the quantization step-size of each block together. The logarithmic quantization index modulation is modified so as to gain the robustness against the amplitude scaling attack. Then, in each low-pass sub-band block, the maximum singular value is chosen to embed watermark bits using the modified logarithmic quantization index modulation (MLQIM). The watermarked image is obtained after carrying out the inverse contourlet transform. The results of experiments demonstrate that the presented algorithm possesses satisfactory imperceptibility and is superior to other common algorithms in terms of the robustness against various attacks.

Fast and Robust Watermarking Method Based on DCT Specific Location

In many studies related to watermarking, spatial-domain methods have a relatively low information-hiding capacity and limited robustness, and transform-domain methods are not applicable in real-time processes because of their considerably high computational time. In this paper, we propose a novel watermarking method based on a discrete cosine transform (DCT), which guarantees robustness and low computational complexity. First, we calculated the DCT coefficient of a specific location. Then, a variation value was calculated according to the embedding bits and quantization steps to modify the coefficient. Last, we embedded watermark bits by directly modifying the pixel values without full-frame DCT. Tests comparing invisibility, robustness, and computational time were conducted for determining the feasibility of the proposed method. The results showed that the proposed method had the faster and the more robust performance than previous studies.

Robust audio watermarking algorithm based on DWT using Fibonacci numbers

This paper presents a blind and robust audio watermarking algorithm developed based on Fibonacci numbers properties and the discrete wavelet transform (DWT) advantages. The method embeds watermark bits in the 6th level approximation subband of DWT at which there is less sensitivity of the human auditory system. The key idea is dividing the 6th level approximation coefficients into small frames and modifying their magnitude based on Fibonacci numbers and watermark bit values. The proposed watermarking method demonstrates a superior robustness against different common attacks (i.e., Gaussian noise addition, Low-pass filter, Resampling, Requantizing, MP3 compression, Amplitude scaling, Echo addition, Time shift, and Cropping). Compared to recently developed methods, the proposed algorithm is much more robust against the most common attacks with capacity as high as 686 bits per second. The results of PEAQ testing verify the quality of watermarked audio signal without significant perceptual distortion. The algorithm allows flexibility in audio watermark algorithm to achieve a balance between robustness and imperceptibility while the capacity is maintained constant by choosing various kinds of sequence.

An improved video key-frame extraction algorithm leads to video watermarking

The epidemic growth of internet services has created a broad attention on digital content authentication and copyright protection. Heading the issue we are going to propose a DCT based novel approach on invisible video watermarking along with an improved video key-frame extraction algorithm. In this article first the key-frames (video bookmarks) of the video sequence are being extracted. In order to identify the video bookmarks, a novel method is proposed based on boundary luminosity analysis that is proven efficient regarding fast camera movement and moving objects in the video frames. A pair of secret keys will be applied during the watermark embedding phase. Our framework embeds watermarks in only those video frames which have been identified as key-frames of that video stream because, the key-frames are mostly kept as it is in different compression algorithms. The low frequency DCT coefficients of key-frames are chosen for watermarking, that again offers robustness to the compression algorithms. Instead of embedding watermark bits directly, a new method is proposed- scaled average. The watermark is perceptually invisible in the video key-frames according to human visual system. At last uncompressed video is re-reconstructed with all frames of the video in appropriate order of appearance. The watermark extraction is blind i.e., except the keys nothing is needed for watermark extraction.

Digital Watermarking in Color Image Based On Joint Between DCT and DWT

The massive distribution and development in the digital images field with friendly software, that leads to produce unauthorized use. Therefore the digital watermarking as image authentication has been developed for those issues. In this paper, we presented a method depending on the embedding stage and extraction stag. Our development is made by combining Discrete Wavelet Transform (DWT) with Discrete Cosine Transform (DCT) depending on the fact that combined the two transforms will reduce the drawbacks that appears during the recovered watermark or the watermarked image quality of each other, that results in effective rounding method, this is achieved by changing the wavelets coefficients of selected DWT sub bands (HL or HH), followed by applying DCT transform on the selected sub band's coefficients, this method focuses on the invisibility for the embedded watermark bits, and the quality for the watermarked image; furthermore it focuses on a subjective for the recovered watermark after extraction stage. The proposed method was evaluated by using simple image quality matrix illustrated in the results, and it was found that the proposed method provide good objective quality, the recovered watermark extracted successfully and the quality of recovered watermark are survived.

A Watermarking Method by Modifying QTCs for HEVC

With rapid development and application in the new video compression standard HEVC, it is necessary new digital watermarking technology capable of application for HEVC. In this paper, we propose a new watermarking method by modifying QTCs (Quantized Transform Coefficients) for HEVC. In proposed method, the watermark is embedded by modifying non-zero QTCs (Quantized Transform Coefficients) of the 4×4 luma transform block of intra predicted I-frame. In order to resist error drift phenomena, we differently modify the significant bits of 4×4 luma block with its direction of intra prediction modes. In decoder, the embedding watermark bits can extract without the need of any extra information. The experimental results show that proposed method is low in computational complexity and is efficiently resist error drift.

Adaptive stereo medical image watermarking using non-corresponding blocks.

Today with the advent of technology in different medical imaging fields, the use of stereoscopic images has increased. Furthermore, with the rapid growth in telemedicine for remote diagnosis, treatment, and surgery, there is a need for watermarking. This is for copyright protection and tracking of digital media. Also, the efficient use of bandwidth for transmission of such data is another concern. In this paper an adaptive watermarking scheme is proposed that considers human visual system in depth perception. Our proposed scheme modifies maximum singular values of wavelet coefficients of stereo pair for embedding watermark bits. Experimental results show high 3D visual quality of watermarked video frames. Moreover, comparison with a compatible state of the art method shows that the proposed method is highly robust against attacks such as AWGN, salt and pepper noise, and JPEG compression.

Robust lossless digital watermarking using integer transform with Bit plane manipulation

In this paper, a robust lossless digital watermarking scheme based on a generalized integer transform in spatial domain is proposed. In the proposed method, data bits are hidden into the cover media by a reversible generalized integer transform with bit plane manipulation. With the reversible transform, data can be hidden in the cover media, and the stego media can be restored to its original form after extraction of the hidden data. In embedding procedure, adaptive bit plane manipulation is applied to increase robustness of the algorithm while keeps good visual quality. To further increase the robustness of the algorithm, we repeatedly embed watermark bits and use majority voting to decode the hidden information in extraction procedure. Furthermore, a threshold is introduced in the algorithm, which helps in choosing regions that would result lower variance for embedding, as regions with lower variance is more robust against JPEG compression. The proposed scheme is quite different from the existing robust lossless data hiding algorithms which are histogram-based. The performance of the proposed scheme is evaluated and compared with state-of-the-arts techniques respect to robustness, data payload capacity and peak signal-to-noise ratio (PSNR). In the experiments, the proposed method can embed more than 10000 bits into 512 by 512 grayscale and medical images, and has around 30 dB in PSNR. In case of small watermark with 100 bits, marked images can have PSNR above 60 dB and with 0.1 bpp in JPEG robustness in the best cases. Conclusively, the robustness of the proposed method is quite good, and the results of hiding capacity and imperceptibility are also satisfactory.

A Robust Watermarking Scheme Based on Maximum Wavelet Coefficient Modification and Optimal Threshold Technique

Digital watermarking has received extensive attention as a new method for copyright protection. This paper proposes a robust watermarking algorithm based on maximum wavelet coefficient modification and optimal threshold technique. The medium wavelet coefficients are randomly permutated according to a secret key and divided into subgroups. We modify the maximum wavelet in each subgroup according to the embedded watermark bits, which can effectively resist attacks. During the extraction process, an optimal threshold value calculated by iterative computation is used to extract the watermark from the watermarked image under different attacks, without using the original image or watermark. Numerous experiments are conducted to evaluate the watermarking performance. Experimental results demonstrate the superiority of our scheme on robustness against content-preserving operations and incidental distortions such as JPEG compression, Gaussian noise, median filter, resizing, cropping, and sharpening.

An imperceptible and robust audio watermarking algorithm

In this paper, we propose a semi-blind, imperceptible, and robust digital audio watermarking algorithm. The proposed algorithm is based on cascading two well-known transforms: the discrete wavelet transform and the singular value decomposition. The two transforms provide different, but complementary, levels of robustness against watermarking attacks. The uniqueness of the proposed algorithm is twofold: the distributed formation of the wavelet coefficient matrix and the selection of the off-diagonal positions of the singular value matrix for embedding watermark bits. Imperceptibility, robustness, and high data payload of the proposed algorithm are demonstrated using different musical clips.

EMD Algorithm for Robust Image Watermarking

Watermarking is process of hiding digital information into another object/signal. To attain robustness information based on image data is transformed in multiple resolution using Wavelet based image watermarking methods. Embedding watermark bits in middle frequency sub images in the wavelet domain is done using Multiband Wavelet Transform (MWT). At this juncture an attempt is made to analyze robustness for different test images. To resist various attacks Empirical Mode Decomposition (EMD) is used. Performance evaluation of an Image watermarking includes robustness, imperceptibility, watermark capacity and security. Index Terms Image enhancement Empirical mode decomposition, Multiband wavelets transformation

Digital watermarking for color images in hue-saturation-value color space

This paper proposes a new watermarking scheme for color images, in which all pixels of the image are used for embedding watermark bits in order to achieve the highest amount of embedding. For watermark embedding, the S component in the hue-saturation-value (HSV) color space is used to carry the watermark bits, while the V component is used in accordance with a human visual system model to determine the proper watermark strength. In the proposed scheme, the number of watermark bits equals the number of pixels in the host image. Watermark extraction is accomplished blindly based on the use of a 3×3 spatial domain Wiener filter. The efficiency of our proposed image watermarking scheme depends mainly on the accuracy of the estimate of the original S component. The experimental results show that the performance of the proposed scheme, under no attacks and against various types of attacks, was superior to the previous existing watermarking schemes.

DWT based coding DNA watermarking for DNA copyright protection

DNA watermarking is a technique for copyright protection and ownership authentication of DNA sequences and ensures the security of private genetic information. This paper addresses issues regarding watermarking DNA coding sequences in the frequency domain that confer mutation resistance, amino acid conservation, and security. Multimedia watermarking is designed for robustness and invisibility mainly based on frequency domain representations. However, frequency domain watermarking for a coding DNA sequence is significantly constrained because the transformation and inverse transformation must be performed while completely conserving the amino acid sequence. In this paper, we present a coding DNA watermarking method in a lifting-based discrete wavelet transform (DWT) domain that focuses on the feasibility of frequency domain watermarking for DNA sequences. Our method divides a coding DNA sequence into a number of subsequences and allocates all codons in subsequences to a numerical code using the histogram ranks of the amino acids. Our method then calculates a set of DWT coefficients for subsequences of synonymous codons and finds a subsequence among them with DWT coefficients that are optimal for embedding watermark bits. Finally, our method substitutes this sequence for a subsequence of codons. To secure the watermark, our method generates the binary watermark based on nonlinear congruential – pseudorandom number generator (NC-PRNG) and randomly selects the embeddable position in the DWT domain of the subsequence. We experimentally verified that our method ensures not only amino acid conservation and security but also resists a point mutation rate of approximately 18.5% point mutations.

Incorporation of perceptually adaptive QIM with singular value decomposition for blind audio watermarking

This paper presents a novel approach for blind audio watermarking. The proposed scheme utilizes the flexibility of discrete wavelet packet transformation (DWPT) to approximate the critical bands and adaptively determines suitable embedding strengths for carrying out quantization index modulation (QIM). The singular value decomposition (SVD) is employed to analyze the matrix formed by the DWPT coefficients and embed watermark bits by manipulating singular values subject to perceptual criteria. To achieve even better performance, two auxiliary enhancement measures are attached to the developed scheme. Performance evaluation and comparison are demonstrated with the presence of common digital signal processing attacks. Experimental results confirm that the combination of the DWPT, SVD, and adaptive QIM achieves imperceptible data hiding with satisfying robustness and payload capacity. Moreover, the inclusion of self-synchronization capability allows the developed watermarking system to withstand time-shifting and cropping attacks.