Objective Evaluation of the Perceptual Quality of 3D Watermarking

In this paper an objective metric to measure the perceptual quality of watermarked 3D meshes is presented. The metric, which is based on a black-box approach, relies on the measurement of the roughness of 3D meshes before and after the insertion of the watermark. To calibrate the metric and to validate it, a set of psychovisual experiments has been carried out. Due to the lack of prior work in this field, a new methodology for the subjective evaluation of the quality of watermarked 3D objects is introduced. The validity of the proposed metric has been tested against a number of different 3D watermarking algorithms, showing an excellent match with the subjective evaluation of the quality stemming from the pshycovisual experiments

A Multi-Scale Roughness Metric for 3D Watermarking Quality Assessment

In this paper an objective metric to measure the perceptual quality of watermarked 3D meshes is presented. The metric relies on a multiscale measurement of the roughness of 3D meshes before and after the watermark insertion. The validity of the proposed metric has been tested against a number of different 3D watermarking algorithms, showing an excellent match with the subjective evaluation of the quality derived from pshycovisual experiments

Robust Image Watermarking Using QR Factorization In Wavelet Domain

A robust blind image watermarking algorithm in wavelet transform domain (WT) based on QR factorization, and quantization index modulation (QIM) technique is presented for legal protection of digital images. The host image is decomposed into wavelet subbands, and then the approximation subband is QR factorized. The secret watermark bit is embedded into the R vector in QR using QIM. The experimental results show that the proposed algorithm preserves the high perceptual quality. It also sustains against JPEG compression, and other image processing attacks. The comparison analysis demonstrates the proposed scheme has better performance in imperceptibility and robustness than the previously reported watermarking algorithms

A NOVEL JOINT PERCEPTUAL ENCRYPTION AND WATERMARKING SCHEME (JPEW) WITHIN JPEG FRAMEWORK

Due to the rapid growth in internet and multimedia technologies, many new commercial applications like video on demand (VOD), pay-per-view and real-time multimedia broadcast etc, have emerged. To ensure the integrity and confidentiality of the multimedia content, the content is usually watermarked and then encrypted or vice versa. If the multimedia content needs to be watermarked and encrypted at the same time, the watermarking function needs to be performed first followed by encryption function. Hence, if the watermark needs to be extracted then the multimedia data needs to be decrypted first followed by extraction of the watermark. This results in large computational overhead. The solution provided in the literature for this problem is by using what is called partial encryption, in which media data are partitioned into two parts - one to be watermarked and the other is encrypted. In addition, some multimedia applications i.e. video on demand (VOD), Pay-TV, pay-per-view etc, allow multimedia content preview which involves „perceptual‟ encryption wherein all or some selected part of the content is, perceptually speaking, distorted with an encryption key. Up till now no joint perceptual encryption and watermarking scheme has been proposed in the literature. In this thesis, a novel Joint Perceptual Encryption and Watermarking (JPEW) scheme is proposed that is integrated within JPEG standard. The design of JPEW involves the design and development of both perceptual encryption and watermarking schemes that are integrated in JPEG and feasible within the „partial‟ encryption framework. The perceptual encryption scheme exploits the energy distribution of AC components and DC components bitplanes of continuous-tone images and is carried out by selectively encrypting these AC coefficients and DC components bitplanes. The encryption itself is based on a chaos-based permutation reported in an earlier work. Similarly, in contrast to the traditional watermarking schemes, the proposed watermarking scheme makes use of DC component of the image and it is carried out by selectively substituting certain bitplanes of DC components with watermark bits. vi ii Apart from the aforesaid JPEW, additional perceptual encryption scheme, integrated in JPEG, has also been proposed. The scheme is outside of joint framework and implements perceptual encryption on region of interest (ROI) by scrambling the DCT blocks of the chosen ROI. The performances of both, perceptual encryption and watermarking schemes are evaluated and compared with Quantization Index modulation (QIM) based watermarking scheme and reversible Histogram Spreading (RHS) based perceptual encryption scheme. The results show that the proposed watermarking scheme is imperceptible and robust, and suitable for authentication. Similarly, the proposed perceptual encryption scheme outperforms the RHS based scheme in terms of number of operations required to achieve a given level of perceptual encryption and provides control over the amount of perceptual encryption. The overall security of the JPEW has also been evaluated. Additionally, the performance of proposed separate perceptual encryption scheme has been thoroughly evaluated in terms of security and compression efficiency. The scheme is found to be simpler in implementation, have insignificant effect on compression ratios and provide more options for the selection of control factor

DWT based digital watermarking fidelity and robustness evaluation

An Image Adaptive Watermarking method based on the Discrete Wavelet Transform is presented in this paper. The robustness and fidelity of the proposed method are evaluated and the method is compared to state-of-the-art watermarking techniques available in the literature. For the evaluation of watermark transparency, an image fidelity factor based on a perceptual distortion metric is introduced. On the other hand, a degradation factor is introduced for the evaluation of watermark robustness against JPEG compression and resizing. The new fidelity metric allows a perceptually aware objective quantification of image fidelity. The suitability of the proposed metric for the fidelity evaluation of still image watermarking is supported by simulation results.Facultad de Informátic

Watermarked 3D Object Quality Assessment

This work concerns the developing of new perceptual metrics for 3D watermarking quality assessment. Any water- marking algorithm, to be effective, requires that the distortions is inevitably introduces into the watermarked media is imperceptible. This requirements is particularly severe for watermarking of 3D objects where the visual quality of the original model has to be preserved, i.e. the visual aspect of the watermarked object have to be the same of the original one. Several methods based on the knowledge of Human Visual System (HVS) have been developed to achieve this goal for still images and video watermarking. Since now, no similar techniques for watermarking of 3D objects exist. Here, we propose a novel experimental methodology for subjective evaluations of 3D objects and two perceptual metrics for quality assessment of watermarked 3D objects. Such metrics have been developed combining roughness estimation of model surface with psychophysical data collected by subjective experiments based on the proposed methodology. The performances of the proposed metrics are deeply analyzed

A NOVEL JOINT PERCEPTUAL ENCRYPTION AND WATERMARKING SCHEME (JPEW) WITHIN JPEG FRAMEWORK

Due to the rapid growth in internet and multimedia technologies, many new commercial applications like video on demand (VOD), pay-per-view and real-time multimedia broadcast etc, have emerged. To ensure the integrity and confidentiality of the multimedia content, the content is usually watermarked and then encrypted or vice versa. If the multimedia content needs to be watermarked and encrypted at the same time, the watermarking function needs to be performed first followed by encryption function. Hence, if the watermark needs to be extracted then the multimedia data needs to be decrypted first followed by extraction of the watermark. This results in large computational overhead. The solution provided in the literature for this problem is by using what is called partial encryption, in which media data are partitioned into two parts - one to be watermarked and the other is encrypted. In addition, some multimedia applications i.e. video on demand (VOD), Pay-TV, pay-per-view etc, allow multimedia content preview which involves „perceptual‟ encryption wherein all or some selected part of the content is, perceptually speaking, distorted with an encryption key. Up till now no joint perceptual encryption and watermarking scheme has been proposed in the literature. In this thesis, a novel Joint Perceptual Encryption and Watermarking (JPEW) scheme is proposed that is integrated within JPEG standard. The design of JPEW involves the design and development of both perceptual encryption and watermarking schemes that are integrated in JPEG and feasible within the „partial‟ encryption framework. The perceptual encryption scheme exploits the energy distribution of AC components and DC components bitplanes of continuous-tone images and is carried out by selectively encrypting these AC coefficients and DC components bitplanes. The encryption itself is based on a chaos-based permutation reported in an earlier work. Similarly, in contrast to the traditional watermarking schemes, the proposed watermarking scheme makes use of DC component of the image and it is carried out by selectively substituting certain bitplanes of DC components with watermark bits. vi ii Apart from the aforesaid JPEW, additional perceptual encryption scheme, integrated in JPEG, has also been proposed. The scheme is outside of joint framework and implements perceptual encryption on region of interest (ROI) by scrambling the DCT blocks of the chosen ROI. The performances of both, perceptual encryption and watermarking schemes are evaluated and compared with Quantization Index modulation (QIM) based watermarking scheme and reversible Histogram Spreading (RHS) based perceptual encryption scheme. The results show that the proposed watermarking scheme is imperceptible and robust, and suitable for authentication. Similarly, the proposed perceptual encryption scheme outperforms the RHS based scheme in terms of number of operations required to achieve a given level of perceptual encryption and provides control over the amount of perceptual encryption. The overall security of the JPEW has also been evaluated. Additionally, the performance of proposed separate perceptual encryption scheme has been thoroughly evaluated in terms of security and compression efficiency. The scheme is found to be simpler in implementation, have insignificant effect on compression ratios and provide more options for the selection of control factor

Metodologia para medidas objetivas de qualidade de vídeo em sistemas de difusão de conteúdos audiovisuais

Tese (doutorado) - Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2013.Este trabalho apresenta uma metodologia para a verificação da qualidade de vídeos em sistemas de difusão em massa. A metodologia proposta apresenta uma nova forma de medir a qualidade de vídeo de forma objetiva sem a utilização de referência para comparação entre as sequências de vídeo original e processada. As medidas no ambiente do usuário são feitas independentemente dos processamentos e da tecnologia da rede de distribuição. A medida da qualidade é feita por meio da inserção de marcas de testes nos vídeos, logo após a produção destes. O processamento e distribuição desses vídeos em um sistema de difusão em massa podem causar degradações que afetam as marcas inseridas. Os vídeos recebidos no ambiente do usuário são captados por meio de uma câmera de vídeo disponível em conjunto com o terminal, que identifica a marca inserida anteriormente à distribuição. Esta captura é feita pelo sistema óptico do ambiente do usuário após uma calibração do sistema. As marcas recebidas passam por um processamento de uma função de qualidade que tem como resultado um valor numérico indicando a qualidade deste vídeo. Como resultados da metodologia, são apresentadas comparações com sistemas de medição de qualidade de vídeo de referência completa utilizados em testes por organismos de padronização. As comparações com os sistemas VQM (Video Quality Metrics) e SSIM (Structural SIMilarity) foram feitas utilizando várias sequências de vídeo de testes, onde foi alcançada uma correlação estatística maior que 80% entre as medidas de qualidade resultantes da nova metodologia e as desses sistemas de referência. ______________________________________________________________________________ ABSTRACTThis work presents a method for verifying the quality of videos on mass broadcasting systems. The proposed method presents a new way of measuring the objective video quality without reference. The measurements in the user’s environment are made regardless of the processing and the broadcasting network technology. A quality measure is made by the insertion of test marks on videos, immediately after the content production. The processing and distribution of these videos on a mass broadcasting system can cause degradations that affect the inserted marks. The video received in the user’s environment is captured by a video camera available along with the video terminal. The captured video should identify the mark inserted before the distribution. This capture is made by the optical system in the user environment after a system calibration. The mark is decoded by the processing of a quality function which results in a numerical value indicating the quality of the video. The results of video quality metrics using this methodology were compared to stan- dardized full reference metrics, VQM (Video Quality Metrics) and SSIM (Structural Similarity), and the linear correlation between this proposed new metrics and the other two metrics was greater than 80%, indicating convergence between these metrics

Modeling quality video metrics of video streaming over optical network

Digital video data, stored in video databases and distributed through communication networks, is subject to various kinds of distortions during acquisition, compression, processing, transmission, and reproduction. Video quality is a characteristic of a video passed through a video transmission/processing system, a formal or informal measure of perceived video degradation (typically, compared to the original video). The impact of encoding and transmission impairments on the perceptual quality video streams is quite complex and depends heavily on the codec type and configuration, and on end system characteristics. Video processing systems may introduce some amounts of distortion or artefacts in the video signal.---------------------------------------------------------------------------Video streaming es vídeo digital transmitido por redes de comunicación y reproducido inmediatamente tras la recepción. Debido a la transmisión sobre redes, el vídeo está sometido a pérdidas de paquetes, delay y jitter. También es necesario comprimir el vídeo previo a la transmisión de este.Ingeniería Técnica en Sonido e Image

Performance and Microarchitectural Analysis for Image Quality Assessment

This thesis presents performance analysis for five matured Image Quality Assessment algorithms: VSNR, MAD, MSSIM, BLIINDS, and VIF, using the VTune ... from Intel. The main performance parameter considered is execution time. First, we conduct Hotspot Analysis to find the most time consuming sections for the five algorithms. Second, we perform Microarchitecural Analysis to analyze the behavior of the algorithms for Intel's Sandy Bridge microarchitecture to find architectural bottlenecks. Existing research for improving the performance of IQA algorithms is based on advanced signal processing techniques. Our research focuses on the interaction of IQA algorithms with the underlying hardware and architectural resources. We propose techniques to improve performance using coding techniques that exploit the hardware resources and consequently improve the execution time and computational performance. Along with software tuning methods, we also propose a generic custom IQA hardware engine based on the microarchitectural analysis and the behavior of these five IQA algorithms with the underlying microarchitectural resources.School of Electrical & Computer Engineerin