101 research outputs found

    Implementation and performance study of image data hiding/watermarking schemes

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    Two data hiding / watermarking techniques for grayscale and color images are presented. One of them is DCT based, another uses DFT to embed data. Both methods were implemented in software utilizing C/C++. The complete listings of these programs are included. A comprehensive reliability analysis was performed on both schemes, subjecting watermarked images to JPEG, SPIRT and MPEG-2 compressions. In addition, the pictures were examined by exposing them to common signal processing operations such as image resizing, rotation, histogram equalization and stretching, random, uniform and Gaussian noise addition, brightness and contrast variations, gamma correction, image sharpening and softening, edge enhancement, manipulation of a channel bit number and others. Methods were compared to each other. It has been shown that the DCT method is more robust and, hence, suitable for watermarking purposes. The DFT scheme exhibits less robustness, but due to its higher capacity is perfect for data hiding purposes

    Robust Watermarking through Dual Band IWT and Chinese Remainder Theorem

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    CRT was a widely used algorithm in the development of watermarking methods. The algorithm produced good image quality but it had low robustness against compression and filtering. This paper proposed a new watermarking scheme through dual band IWT to improve the robustness and preserving the image quality. The high frequency sub band was used to index the embedding location on the low frequency sub band. In robustness test, the CRT method resulted average NC value of 0.7129, 0.4846, and 0.6768 while the proposed method had higher NC value of 0.7902, 0.7473, and 0.8163 in corresponding Gaussian filter, JPEG, and JPEG2000 compression test. Meanwhile the both CRT and proposed method had similar average SSIM value of 0.9979 and 0.9960 respectively in term of image quality. The result showed that the proposed method was able to improve the robustness and maintaining the image quality

    A New Blind Method for Detecting Novel Steganography

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    Steganography is the art of hiding a message in plain sight. Modern steganographic tools that conceal data in innocuous-looking digital image files are widely available. The use of such tools by terrorists, hostile states, criminal organizations, etc., to camouflage the planning and coordination of their illicit activities poses a serious challenge. Most steganography detection tools rely on signatures that describe particular steganography programs. Signature-based classifiers offer strong detection capabilities against known threats, but they suffer from an inability to detect previously unseen forms of steganography. Novel steganography detection requires an anomaly-based classifier. This paper describes and demonstrates a blind classification algorithm that uses hyper-dimensional geometric methods to model steganography-free jpeg images. The geometric model, comprising one or more convex polytopes, hyper-spheres, or hyper-ellipsoids in the attribute space, provides superior anomaly detection compared to previous research. Experimental results show that the classifier detects, on average, 85.4% of Jsteg steganography images with a mean embedding rate of 0.14 bits per pixel, compared to previous research that achieved a mean detection rate of just 65%. Further, the classification algorithm creates models for as many training classes of data as are available, resulting in a hybrid anomaly/signature or signature-only based classifier, which increases Jsteg detection accuracy to 95%

    ROBUST INTEGER HAAR WAVELET BASED WATERMARKING USING SINGULAR VALUE DECOMPOSITION

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    This paper proposed a hybrid watermarking method that used dither quantization of Singular Value Decomposition (SVD) on average coefficients of Integer Haar Wavelet Transform (IHWT). The watermark image embeds through dither quantization process on singular coefficients value. This scheme aims to obtain the higher robustness level than previous method which performs dither quantization of SVD directly on image pixels value. The experiment results show that the proposed method has proper watermarked images quality above 38dB. The proposed method has better performance than the previous method in term of robustness against several image processing attacks. In JPEG compression with Quality Factor of 50 and 70, JPEG2000 compression with Compression Ratio of 5 and 3, average filtering, and Gaussian filtering, the previous method has average Normalized Correlation (NC) values of 0.8756, 0.9759, 0.9509, 0.9905, 0.8321, and 0.9297 respectively. While, the proposed method has better average NC values of 0.9730, 0.9884, 0.9844, 0.9963, 0.9020, and 0.9590 respectively

    A novel QR-code based watermarking scheme for digital rights

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    This paper presents a digital rights protection scheme for both colour and grayscale images using a novel approach that combines watermarking and cryptography. The schema involves two parties: the owner of the digital rights and a generic user who acquired some rights on a copy of the image that will be watermarked. The watermark, a QR code derived from a signed “License Agreement”, is repeatedly inserted, and scrambled, by the image right’s owner, into the frequency components of the image, thus producing the watermarked image. The schema, a non-blind type, achieves good perceptive quality and fair robustness using the 3rd level of the Discrete Wavelet Transform. The experimental results show that, inserting more occurrences of a scrambled QR code, the proposed algorithm is quite resistant to JPEG compression, rotation, cropping and salt & peeper noise

    Data Hiding Techniques In Digital Images

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    With literally millions of images moving on the Internet each year it is safe to say that hiding data in digital image is of real concern to many in the security field. Therefore how to protect secret messages during transmission becomes an important issue. Hiding data provides a good layer of protection on the secret message, so the purpose of this thesis is to study the data hiding techniques in digital images as a new and powerful technology capable of solving important practical problems. Depending on what information in which form is hidden in the digital images, one can distinguish two types of data hiding techniques, spatial domain techniques, and frequency domain techniques. In the spatial domain techniques, a digital image serves as a carrier for a secret message. For instance, by replacing the least significant bit of each pixel in the carrier image with the secret message after changing it to stream of bits, the changes to the carrier image will be imperceptible and the secret message will be masked by carrier image. In this side, two programs had been implemented using MATLAB program to illustrate the main idea involved in least significant technique (low bit encoding), and the other to illustrate the masking technique inside the carrier image. In the frequency domain techniques, a short message is embedded in the carrier image in a robust algorithm. Robustness means the ability to survive common image processing operations, such as lossy compression, filtering, noise adding, geometrical transformations, etc. So in this technique two programs had been implemented to illustrate the main idea involved in frequency domain, one with the Fast Fourier Transform (FFT), and the other with the Discrete Wavelet Transform (DWT). After all these studies, one of the algorithms in the masking technique is developed and implemented using JAVA program to embed message into true color image with a good quality and higher capacity. Beside that the carrier images in different techniques were examined by exposing them to common signal processing operations such as image resizing, rotation, histogram equalization, lossy Compression, and Gaussian noise addition to illustrate the characteristic of the data hiding techniques, such as hiding capacity, robustness, undetectability, and perceptual transparency Finally, it has been shown that the frequency transformation techniques are more robust, and hence suitable for water marking and data hiding purpose. The spatial domain techniques exhibit loss robustness but due to its higher capacity and good quality are perfect for data hiding purposes

    Data hiding in multimedia - theory and applications

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    Multimedia data hiding or steganography is a means of communication using subliminal channels. The resource for the subliminal communication scheme is the distortion of the original content that can be tolerated. This thesis addresses two main issues of steganographic communication schemes: 1. How does one maximize the distortion introduced without affecting fidelity of the content? 2. How does one efficiently utilize the resource (the distortion introduced) for communicating as many bits of information as possible? In other words, what is a good signaling strategy for the subliminal communication scheme? Close to optimal solutions for both issues are analyzed. Many techniques for the issue for maximizing the resource, viz, the distortion introduced imperceptibly in images and video frames, are proposed. Different signaling strategies for steganographic communication are explored, and a novel signaling technique employing a floating signal constellation is proposed. Algorithms for optimal choices of the parameters of the signaling technique are presented. Other application specific issues like the type of robustness needed are taken into consideration along with the established theoretical background to design optimal data hiding schemes. In particular, two very important applications of data hiding are addressed - data hiding for multimedia content delivery, and data hiding for watermarking (for proving ownership). A robust watermarking protocol for unambiguous resolution of ownership is proposed

    A digital signature and watermarking based authentication system for JPEG2000 images

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    In this thesis, digital signature based authentication system was introduced, which is able to protect JPEG2000 images in different flavors, including fragile authentication and semi-fragile authentication. The fragile authentication is to protect the image at code-stream level, and the semi-fragile is to protect the image at the content level. The semi-fragile can be further classified into lossy and lossless authentication. With lossless authentication, the original image can be recovered after verification. The lossless authentication and the new image compression standard, JPEG2000 is mainly discussed in this thesis

    New steerable pyramid steganography algorithm resistant to the Fisher Linear Discriminant steganalysis

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    This paper describes a new steganography algorithm based on a steerable pyramid transform of a digital image and the steganalysis of the existence of secret messages hidden by this new method. The data embedding process uses the elements of a Lee and Chen steganography algorithm which is adapted to the steerable pyramid transform domain. This article describes the Fisher Linear Disriminant (FLD) analysis and its steganalysis application, too. The main part of the paper is the description of the conducted research and the results of FLD steganalysis of stegoimages produced by the new steganography algorithm
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