Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 18 of 18 for “"JPEG compression"”.
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A study of probability distributions of DCT coefficients in JPEG compression
The Discrete Cosine Transform (DCT) used in JPEG compression has shown excellent energy compaction properties that rival that of the ideal Karhunen-Loeve Transform. Lossy compression in JPEG is achieved by distorting 8x8 block DCT coefficients through quantization. It has been shown in literature …
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Study of joint embedding and compression on JPEG compression scheme using multiple codebook data hiding
… implementation of a joint embedding and compression scheme. It presents a study of Type III data embedding technique using multiple codebook design on JPEG-85 compression scheme. The application of the above technique is compared with the Type III data embedding techniques using single …
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Compression artifact suppression for color images with dual-domain SE-ARResNet
JPEG compression has been a popular lossy image compression technique and is widely used in digital imaging. Restoring high-quality images from their compressed JPEG counterparts, however, is an ill-posed inverse problem but could be of great use in improving the visual quality of images. With the …
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Digital Watermarking Based Image and Video Quality Evaluation
… the image degradation characteristics under JPEG compression. This iterative process provides high accuracy for quality evaluation. However, it results in relatively high computational complexity. As an improvement, a tree structure based scheme is proposed to assign adaptive watermark …
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Digital image forensics
… tampering detection and classification of double JPEG compression are the two major subjects studied. Since any manipulation applied to digital images changes image statistics, identifying statistical artifacts becomes critically important in image forensics. In this thesis, a few typical forensic …
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Efficient image compression system using a CMOS transform imager
… on the implementation of the efficient image compression system among the many potential applications of a transform imager system. The study includes implementing the image compression system using a transform imager, developing a novel image compression algorithm for the system, and …
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Image statistical frameworks for digital image forensics
… is proposed, capable of obfuscating double JPEG compression artifacts, which may vital information for image forensics, for instance, digital image tampering detection. Shrink-and-zoom (SAZ) attack, the proposed scheme, is simply based on image resizing and bilinear interpolation. The …
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A feature-based fingerprinting scheme robust to desynchronization
… interleaving, addition of Gaussian noise, JPEG compression (with quality factor Q=45), cropping (50% of the image area), affine transforms, homography and image warping.
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RST invariant digital image watermarking
… is in a reasonable range, and very robust to JPEG compression and other attacks.
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Design and analysis of Discrete Cosine Transform-based watermarking algorithms for digital images. Development and evaluation of blind Discrete Cosine Transform-based watermarking algorithms for copyright protection of digital images using handwritten signatures and mobile phone numbers.
… methods are shown to be robust against JPEG compression, removal attack, additive noise, cropping, scaling, small degrees of rotation, affine, contrast enhancements, low-pass, median filtering and Stirmark attacks. The algorithms have been examined using a library of approximately 40 …
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Design and analysis of Discrete Cosine Transform-based watermarking algorithms for digital images. Development and evaluation of blind Discrete Cosine Transform-based watermarking algorithms for copyright protection of digital images using handwritten signatures and mobile phone numbers
… methods are shown to be robust against JPEG compression, removal attack, additive noise, cropping, scaling, small degrees of rotation, affine, contrast enhancements, low-pass, median filtering and Stirmark attacks. The algorithms have been examined using a library of approximately 40 …
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Combined robust and fragile watermarking algorithms for still images. Design and evaluation of combined blind discrete wavelet transform-based robust watermarking algorithms for copyright protection using mobile phone numbers and fragile watermarking algorithms for content authentication of digital still images using hash functions.
… the robustness against different attacks such as JPEG compression, scaling, salt and pepper noise, Gaussian noise, filters and other image processing compared to DCT based algorithms. The authenticity of the images were assessed by using a fragile watermarking algorithm by using hash function …
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Multimedia Forensics: From Image manipulation to the Deep Fake.New Threats in the Social Media Era.
… (focusing particularly on the double compressed JPEG images), until arriving to the emerging phenomenon of the DeepFakes. Nowadays the social media ecosystem includes hundreds of applications, based on web and mobile technologies and able to allow people to communicate easily and/or to share …
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Steganography-based secret and reliable communications: Improving steganographic capacity and imperceptibility
… table for Joint Photographic Experts Group (JPEG) compression instead of 8x8. Then, the quality of JPEG stego images was enhanced by using optimised quantisation tables instead of the default tables. The second method, the hybrid method, was based on using optimised quantisation tables and …
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Dynamically Reconfigurable Architectures and Systems for Time-varying Image Constraints (DRASTIC) for Image and Video Compression
… variety of applications in both image and video compression. In each application, a family of Pareto-optimal configurations are developed that allow fine control in the rate-quality-power/energy optimization space. The term Dynamically Reconfiguration Architecture Systems for Time-varying Image …
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Information security based on temporal order and ergodic matrix
… types of image processing attacks, such as JPEG compression, median filtering, average filtering, histogram equalization, rotation, cropping, Gaussian noise, speckle noise, salt-pepper noise. In general, the proposed method is a useful tool for ownership identification and copyright …
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Real-time Realistic Rendering And High Dynamic Range Image Display And Compression
… range devices and the development of data compression algorithms to store and recover the corresponding large amounts of detail found in HDR images. This dissertation presents our contributions relevant to these issues. Our contributions to high dynamic range image processing include tone …
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Investigation of the effects of image compression on the geometric quality of digital protogrammetric imagery
… that deals with this problem is called image compression. Image compression is a necessity for the utilisation of large digital images in softcopy photogrammetry, remote sensing, and multimedia GIS. Numerous image Compression standards exist today with the common goal of reducing the number of …