Comparative analysis of LSB, DCT and DWT for Digital Watermarking

Abstract: Steganography is the technique of hiding any secret information like text, image or video behind a cover file. Audio steganography is one of the widespread data hiding techniques that embeds secret data in audio signals. The secret data is hidden in a way that unauthorized people are not aware of the existence of the embedded data and without changing the quality of the audio signal (cover audio). Data hiding in audio signals has various applications such as protection of copyrighted audio signals, secret communication, hiding data that may influence the security and safety of governments and personnel. This paper proposes an efficient steganography scheme based on sample comparison in Discrete Wavelet Transform (DWT) domainwhere the cover audio is decomposed into several multi sub-bands, and then selected coefficients of details are changed by a threshold value depending on the embedding cipher image bit. This approach employs an original image component to perform RSA encryption on it, then cipher bits are embedded in the details components of the audio signal according to a predetermined threshold value. The performance of the algorithm has been estimated extensively against attacks, and simulation results are presented to prove the robustness of the proposed algorithm.

Abstract: The vulnerability of digital audio signals for different types of risks requires an imperceptible and robust digital audio watermarking scheme. In this research, we propose creating one such imperceptible and robust hybrid watermarking scheme based on a discrete wavelet transform (DWT) and Schur decomposition hybrid method. The proposed scheme embeds the foreground bits of the watermarking image into the least significant bit of the diagonal coefficients of the triangular matrix S generated from Schur decomposition. Schur decomposition is applied on the second sub-band HL2 generated from applying a second-level 2D-Haar DWT on the first channel of the original audio signal. We analyze the proposed digital audio watermarking scheme’s performance in terms of signal to noise ratio (SNR), objective difference grades (ODG), and subjective difference grades (SDG) that resulting 81.43, 4.78 and 0.184, respectively. The resulting of payload capacity, NC, and BER are as high as 319.29 bps, 0.9911, and 0.0135, respectively. Experimental results confirm that the proposed scheme is inaudible and robust against common types of attacks such as Gaussian noise, re-quantization, re-sampling, low-pass filter, high-pass filter, echo, MP3 compression, and cropping. In comparison with state-of-the-art audio watermarking schemes, the proposed scheme’s performance is superior in term of imperceptibility, robustness, and data payload size.

Abstract: data in an image file is needed by its owner to set his ownership in a logo as a watermark embedded in the image file. Hiding the logo in the image was done in several methods. One of the method is domain transform using 2D-DCT in which data is embedded in frequency domain of the image. First, the host RGB image is converted to certain color space. The available and chosen color spaces are RGB, YCbCr or NTSC. The layer in which the watermark is embedded also can be selected. The available choices are 1 st layer, 2 nd layer, 3 rd layer, 1 st & 2 nd layer, 2 nd & 3 rd layer, 1 st & 3 rd layer and all layers. After the selected layer of image in certain color space is transformed in block based to frequency domain by DCT, one bit watermark is embedded on the AC coefficient of each block such a way that the bit is represented by specific value called delta in a zigzag and vary length of pixel. The vary parameters optimized by Genetics Algorithm are selected color space, selected layer, block size, length of pixel to be embedded by one bit watermark, and delta. Bit “1” is represented by +delta, and bit “0” is represented by –delta in vary length of pixel after zigzag. The simulation result performs that GA is useful to search the value of parameter that produces controllable the combination between robustness, invisibility and capacity. Thus, GA improves the method by determining the exact value of parameter achieving BER, PSNR and payload.

Abstract: In this study, a wavelet transform based on Meyer algorithm with edge-angle tracking capability is proposed for edge and blocking artifact reduction of an image, during image compression processes. This new proposed scheme is quite different from the conventional curvelet scheme, which can be viewed as using post-processing, after wavelet transform, to track only the edge of a high-frequency section of wavelet coefficients . However, the proposed wavelet transform scheme based on Meyer algorithm is with a complete wavelet design procedure, which is suitable for multiresolution analysis ; it possesses the orthonormal property of conventional wavelet transforms. From computer simulation, we verify the merits of the proposed scheme over the conventional approaches, in terms of achieving better performance based on the subjective and objective (e.g., the peak signal-to-noise ratio) analysis.

Abstract: The multimedia revolution has made a strong impact on our society. The explosive growth of Internet access to this digital information has generated new opportunities and challenges. The ease of editing and duplicating information in the digital domain has created copyright protection concerns for content providers. Various schemes to embed secondary data in digital media have been investigated to preserve copyright and to discourage unauthorized duplication. In order to achieve the required level of protection to digital information, digital watermarking is a viable solution. This paper proposes a novel invisible watermarking scheme: a Discrete Cosine Transform (DCT) domain based watermark embedding and blind extraction algorithm for copyright protection of color images. The proposed algorithm is optimized in terms of robustness, computational load, and quality of the image. Testing of the proposed watermarking scheme’s robustness and security via different benchmarks as well as comparison with a Discrete Wavelet Transform (DWT) approach proves its resilience to digital attacks. The results show that the Peak Signal to Noise Ratio (PSNR) value obtained under no attack conditions in the proposed algorithm is above 41.81 dB, which is higher than most of the existing watermark algorithms. The results from the detector’s response also show that the proposed algorithm has a better security performance than most of the existing algorithms. The architecture for hardware implementation of the proposed algorithm is also presented and the results from the architecture show a PSNR value of 44.37 dB. This verifies that the presented algorithm is more effective than existing algorithms such as image adaptive watermarking, image adaptive watermark creation, zerotree wavelet, and 9/7 biorthogonal wavelet lifting.

Abstract: We review developments in transparent data embedding and watermarking for audio, image, and video. Data-embedding and watermarking algorithms embed text, binary streams, audio, image, or video in a host audio, image, or video signal. The embedded data are perceptually inaudible or invisible to maintain the quality of the source data. The embedded data can add features to the host multimedia signal, e.g., multilingual soundtracks in a movie, or provide copyright protection. We discuss the reliability of data-embedding procedures and their ability to deliver new services such as viewing a movie in a given rated version from a single multicast stream. We also discuss the issues and problems associated with copy and copyright protection and assess the viability of current watermarking algorithms as a means for protecting copyrighted data.

Abstract: Digital watermarking has been proposed as a solution to the problem of copyright protection of multimedia data in a networked environment. It makes possible to tightly associate to a digital document a code allowing the identification of the data creator, owner, authorized consumer, and so on. In this paper a new watermarking algorithm for digital images is presented: the method, which operates in the frequency domain, embeds a pseudo-random sequence of real numbers in a selected set of DCT coefficients. After embedding, the watermark is adapted to the image by exploiting the masking characteristics of the human visual system, thus ensuring the watermark invisibility. By exploiting the statistical properties of the embedded sequence, the mark can be reliably extracted without resorting to the original uncorrupted image. Experimental results demonstrate that the watermark is robust to several signal processing techniques, including JPEG compression, low pass and median filtering, histogram equalization and stretching, dithering, addition of Gaussian noise, resizing, and multiple watermarking.

Abstract: A watermark is an invisible mark placed on an image that is designed to identify both the source of an image as well as its intended recipient. The authors present an overview of watermarking techniques and demonstrate a solution to one of the key problems in image watermarking, namely how to hide robust invisible labels inside grey scale or colour digital images.

Abstract: A watermark is all invisible mark placed on an image that can only be detected when the image is compared with the original. This mark is designed to identify both the source of a document as well as its intended recipient. This paper discusses various techniques for embedding such marks in grey scale and colour digital images. It begins specifying the requirements that an effective image watermarking scheme must possess, followed by a review of current and novel techniques based on image transforms.

Abstract: A DCT-based image watermarking algorithm is described, where the original image is not required for watermark recovery, and is achieved by inserting the watermark in subimages obtained through subsampling.