348 research outputs found

    Digital rights management techniques for H.264 video

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    This work aims to present a number of low-complexity digital rights management (DRM) methodologies for the H.264 standard. Initially, requirements to enforce DRM are analyzed and understood. Based on these requirements, a framework is constructed which puts forth different possibilities that can be explored to satisfy the objective. To implement computationally efficient DRM methods, watermarking and content based copy detection are then chosen as the preferred methodologies. The first approach is based on robust watermarking which modifies the DC residuals of 4×4 macroblocks within I-frames. Robust watermarks are appropriate for content protection and proving ownership. Experimental results show that the technique exhibits encouraging rate-distortion (R-D) characteristics while at the same time being computationally efficient. The problem of content authentication is addressed with the help of two methodologies: irreversible and reversible watermarks. The first approach utilizes the highest frequency coefficient within 4×4 blocks of the I-frames after CAVLC en- tropy encoding to embed a watermark. The technique was found to be very effect- ive in detecting tampering. The second approach applies the difference expansion (DE) method on IPCM macroblocks within P-frames to embed a high-capacity reversible watermark. Experiments prove the technique to be not only fragile and reversible but also exhibiting minimal variation in its R-D characteristics. The final methodology adopted to enforce DRM for H.264 video is based on the concept of signature generation and matching. Specific types of macroblocks within each predefined region of an I-, B- and P-frame are counted at regular intervals in a video clip and an ordinal matrix is constructed based on their count. The matrix is considered to be the signature of that video clip and is matched with longer video sequences to detect copies within them. Simulation results show that the matching methodology is capable of not only detecting copies but also its location within a longer video sequence. Performance analysis depict acceptable false positive and false negative rates and encouraging receiver operating charac- teristics. Finally, the time taken to match and locate copies is significantly low which makes it ideal for use in broadcast and streaming applications

    A Framework for Multimedia Data Hiding (Security)

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    With the proliferation of multimedia data such as images, audio, and video, robust digital watermarking and data hiding techniques are needed for copyright protection, copy control, annotation, and authentication. While many techniques have been proposed for digital color and grayscale images, not all of them can be directly applied to binary document images. The difficulty lies in the fact that changing pixel values in a binary document could introduce Irregularities that is very visually noticeable. We have seen but limited number of papers proposing new techniques and ideas for document image watermarking and data hiding. In this paper, we present an overview and summary of recent developments on this important topic, and discuss important issues such as robustness and data hiding capacity of the different techniques

    Development Of A Robust Blind Digital Video Watermarking Algorithm Using Discrete Wavelet Transform

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    Video watermarking technology enables us to hide an imperceptible, robust, and secure data in digital or analog video. This data can be used for tracking, fingerprinting, copyright infringement detection or any other application that requires some hidden data. Video watermarking can be achieved by either applying still image technologies to each frame of the movie or by using dedicated methods which exploit inherent features of the video sequence. There is a complex trade-off between three requirements in digital watermarking: robustness against noise and attacks, imperceptibility or invisibility, and capacity, which represent the amount of data, i.e., the number of bits encoded by the watermark. However, these three requirements conflict with each other. Increasing the watermark strength makes the system more robust but unfortunately decreases the perceptual quality. Whereas, increasing the capacity of the watermark decreases the robustness.In the production chain, video compression is usually applied before broadcasting or before transferring the video to other devices. In order to be robust against format conversions, the watermark has to be inserted before compression. Therefore, uncompressed video format has been used in the research undertaken. On the other hand, a random key is used to choose the frames to be watermarked to increase the security level of the algorithm and discourage piracy. The aim of this research is to develop a video watermarking algorithm to embed a binary image inside the uncoded video stream that acts as a logo. A mid-band discrete wavelet transform coefficients of the selected frames are chosen to be the hosted region in the frequency domain. An inverse transformation should be taken in order to get the desired watermarked video shot. In extraction process the watermark is extracted from the marked video directly without access to the original video. The experiment results showed that the proposed scheme provides better quality watermarked videos in term of watermark invisibility to human eyes. Results also indicated that obtaining average peak signal to noise ratio (PSNR) equals 41.59dB as compared with 38.48dB in the case of direct embedding. In addition, the scheme is robust against video processing operations, such as MPEG compression which could be successfully recovered. In conclusion, modifying the wavelet coefficients depending only on the logo object's pixels highly improve the invisibility and at the same time providing a good robustness level

    Robust drift-free bit-rate preserving H.264 watermarking

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    International audienceThis paper presents a novel method for open-loop watermarking of H.264/AVC bitstreams. Existing watermarking algorithms designed for previous encoders, such as MPEG-2 cannot be directly applied to H.264/AVC, as H.264/AVC implements numerous new features that were not considered in previous coders. In contrast to previous watermarking techniques for H.264/AVC bitstreams, which embed the information after the reconstruction loop and perform drift compensation, we propose a completely new intra-drift-free watermarking algorithm. The major design goals of this novel H.264/AVC watermarking algorithm are runtime-efficiency, high perceptual quality, (almost) no bit-rate increase and robustness to re-compression. The watermark is extremely runtime-efficiently embedded in the compressed domain after the reconstruction loop, i.e., all prediction results are reused. Nevertheless, intra-drift is avoided, as the watermark is embedded in such a way that the pixels used for the prediction are kept unchanged. Thus, there is no drift as the pixels being used in the intra-prediction process of H.264/AVC are not modified. For watermark detection, we use a two-stage cross-correlation. Our simulation results confirm that the proposed technique is robust against re-encoding and shows a negligible impact on both the bit-rate and the visual quality

    Study on high Performance and Effective Watermarking Scheme using Hybrid Transform (DCT-DWT)

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    Nowadays healthcare infrastructure depends on Hospital Information Systems (HIS), Radiology Information Systems (RIS),Picture archiving and Communication Systems (PACS) as these provide new ways to store, access and distribute medical data . It eliminates the security risk. Conversely, these developments have introduced new risks for unsuitable deployment of medical information flowing in open networks, provided the effortlessness with which digital content can be manipulated. It is renowned that the integrity and confidentiality of medical data is a serious topic for ethical and legal reasons. Medical images need to be kept intact in any condition and prior to any operation as well need to be checked for integrity and verification. Watermarking is a budding technology that is capable of assisting this aim. In recent times, frequency domain watermarking algorithms have gained immense importance due to their widespread use. Subsequently, the watermark embedding and extraction are performed in frequency domain using the presented scheme. The proposed watermarking scheme, the watermark extraction compared with the original image for calculating SSIM.The effectiveness of the proposed watermarking scheme is demonstrated with the aid of experimental results
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