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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Inverse Discrete Cosine Transform by Bit Parallel Implementation and Power Comparision

Bhardwaj, Divya Anshu January 2003 (has links)
<p>The goal of this project was to implement and compare Invere Discrete Cosine Transform using three methods i.e. by bit parallel, digit serial and bit serial. This application describes a one dimensional Discrete Cosine Transform by bit prallel method and has been implemented by 0.35 ìm technology. When implementing a design, there are several considerations like word length etc. were taken into account. The code was implemented using WHDL and some of the calculations were done in MATLAB. The VHDL code was the synthesized using Design Analyzer of Synopsis; power was calculated and the results were compared.</p>
192

Digital videoväxel / Digital video switch

Länger, Henrik, Eriksson, Olle January 2004 (has links)
<p>This thesis discusses the possibilities to distribute digital video in a military vehicle. Today, an analogue system is used, which has a maximum capacity of eighteen video sources and the same number of monitors. The purpose of this thesis is to increase the systems capabilities regarding secure distribution and additional functions. </p><p>Both software and hardware tests are made to investigate the features of the digital video standard MPEG-2. Both the coding delay and the image quality are of great interest. Another digital video standard, DV, is considered as an alternative to MPEG-2. </p><p>Apart from different coding techniques, this work describes some distribution techniques like TCP/IP, DVB-C and USB.</p>
193

Facial Features Tracking using Active Appearance Models

Fanelli, Gabriele January 2006 (has links)
<p>This thesis aims at building a system capable of automatically extracting and parameterizing the position of a face and its features in images acquired from a low-end monocular camera. Such a challenging task is justified by the importance and variety of its possible applications, ranging from face and expression recognition to animation of virtual characters using video depicting real actors. The implementation includes the construction of Active Appearance Models of the human face from training images. The existing face model Candide-3 is used as a starting point, making the translation of the tracking parameters to standard MPEG-4 Facial Animation Parameters easy.</p><p>The Inverse Compositional Algorithm is employed to adapt the models to new images, working on a subspace where the appearance is "projected out" and thus focusing only on shape.</p><p>The algorithm is tested on a generic model, aiming at tracking different people’s faces, and on a specific model, considering one person only. In the former case, the need for improvements in the robustness of the system is highlighted. By contrast, the latter case gives good results regarding both quality and speed, with real time performance being a feasible goal for future developments.</p>
194

Implementering av 1D-DCT

Zilic, Edmin January 2006 (has links)
<p>IDCT (Inverse Discrete Cosine Transform) is a common algorithm being used with image and sound decompression. The algorithm is a Fourier related transform which can occur in many different types like, one-dimensional, two-dimensional, three-dimensional and many more.</p><p>The goal with this thesis is to create a fast and low effect version of two-dimensional IDCT algorithm, where techniques as multiple-constant multiplication and subexpression sharing plus bit-serial and bit-parallel arithmetic are used.</p><p>The result is a hardware implementation with power consumption at 19,56 mW.</p>
195

Design of Static Demultiplexing for Digital-TV

To, Kam Hung, Mehmedagic, Erna January 2007 (has links)
<p>All digital-TV receivers that are existent on the market today include some sort of a multiplexer which filters the data, the sound and the picture from the digital stream. These de-multiplexers are rather complex and general. The purpose of this Master Thesis is to develop a de-multiplexer which would solely filter one specific type of information out of the data stream, in our case the name of the network.</p><p>The main task of this project contains a close study of MPEG2 and the transport streams in order to find a solution and create a static de-multiplexer. Another part of this project is to choose an adequate method for the control and data communication. We will study the bus protocols I2C and SPI.</p><p>Finally we will construct the entire circuit after having chosen the Development Environment, DE and considered all the different circuit designs suitable for our task as well as the working at a low production cost, which is of course an important factor and challenge. The first part of construction will be made in Very High Speed Integrated Circuit Hardware Description Language, VHDL, code and once the program is tested and working we will implement it and create the circuit. We will run a test of the final circuit test by filtering a near satellite signal and the get the name of the aimed network.</p>
196

A Cost Shared Quantization Algorithm and its Implementation for Multi-Standard Video CODECS

2012 December 1900 (has links)
The current trend of digital convergence creates the need for the video encoder and decoder system, known as codec in short, that should support multiple video standards on a single platform. In a modern video codec, quantization is a key unit used for video compression. In this thesis, a generalized quantization algorithm and hardware implementation is presented to compute quantized coefficient for six different video codecs including the new developing codec High Efficiency Video Coding (HEVC). HEVC, successor to H.264/MPEG-4 AVC, aims to substantially improve coding efficiency compared to AVC High Profile. The thesis presents a high performance circuit shared architecture that can perform the quantization operation for HEVC, H.264/AVC, AVS, VC-1, MPEG- 2/4 and Motion JPEG (MJPEG). Since HEVC is still in drafting stage, the architecture was designed in such a way that any final changes can be accommodated into the design. The proposed quantizer architecture is completely division free as the division operation is replaced by multiplication, shift and addition operations. The design was implemented on FPGA and later synthesized in CMOS 0.18 μm technology. The results show that the proposed design satisfies the requirement of all codecs with a maximum decoding capability of 60 fps at 187.3 MHz for Xilinx Virtex4 LX60 FPGA of a 1080p HD video. The scheme is also suitable for low-cost implementation in modern multi-codec systems.
197

Partial Encryption Of Video For Communication And Storage

Yuksel, Turan 01 September 2003 (has links) (PDF)
In this study, a new method is proposed to protect video data through partial encryption. Unlike previous methods, the bit rate of the encrypted portion can be controlled. In order to accomplish this task, a simple model for the time to break the partial encryption by a chipertext-only attack is defined. Then, the encrypted bit budget distribution strategy maximizing the time subject to the bitrate constraint is found. An algorithm to estimate the model parameters is constructed and it isthen implemented over an MPEG-4 natural video codec together with the bit budget distribution strategy. The encoder is tested with various image sequences and the output is analyzed. In addition to the developed video encryption method, a file format is defined to store encryption related side information.
198

An Iterative MPEG Super-Resolution with an Outer Approximation of Framewise Quantization Constraint

SAKANIWA, Kohichi, YAMADA, Isao, ONO, Toshiyuki, HASEGAWA, Hiroshi 01 September 2005 (has links)
No description available.
199

Split-Domain TCP-Friendly Protocol For MPEG-4 Adaptive Rate Video Streaming Over 3G Networks

Ha, Rick Wan Kei January 2002 (has links)
The imminent inception of third-generation (3G) mobile communication networks offers an unprecedented opportunity for the development of video streaming applications through wireless Internet access. Different design challenges exist in implementing video streaming connections spanning both wired and wireless domains. A split-domain TCP-friendly streaming video transmission protocol is presented based on adaptive rate encoding in the MPEG-4 video format. Network simulations are conducted to demonstrate the benefits and viability of such a video streaming scheme over existing options. Further feature enhancements and refinements are necessary for the proposed protocol to achieve its full potential.
200

Tatouage pour le renforcement de la qualité audio des systèmes de communication bas débit

Gharbi, Imen 16 January 2013 (has links) (PDF)
L'objectif de cette thèse est d'étudier l'idée du tatouage dans le traitement du son.Les recherches en tatouage audio se sont principalement tournées vers des applications sécuritaires ou de transmission de données auxiliaires. Une des applications visées par ce concept consiste à améliorer la qualité du signal hôte ayant subi des transformations et ceci en exploitant l'information qu'il véhicule. Le tatouage audio est donc considéré comme mémoire porteuse d'informations sur le signal originel. La compression à bas débit des signaux audio est une des applications visée par ce concept. Dans ce cadre, deux objectifs sont proposés : la réduction du pré-écho et de l'amollissement d'attaque, deux phénomènes introduits par les codeurs audio perceptifs, en particulier les codeurs AAC et MP3; la préservation de l'harmonicité des signaux audio dégradée par les codeurs perceptifs à extension de bande, en particulier le codeur HE-AAC.La première partie de ce manuscrit présente les principes de base des systèmes de codage bas débit et étudie les différentes distorsions introduites par ces derniers. Fondées sur cette étude, deux solutions sont proposées. La première, visant principalement la réduction du pré-écho, consiste à corriger l'enveloppe temporelle du signal après réception en exploitant la connaissance a priori de l'enveloppe temporelle du signal original, supposée transmise par un canal auxiliaire à faible débit (< 500 bits/s). La seconde solution vise à corriger les ruptures d'harmonicité générées par les codeurs à extension de bande. Ce phénomène touche essentiellement les signaux fortement harmoniques (exemple : violon) et est perçu comme une dissonance. Une préservation de l'harmonicité des signaux audio par des opérations de translation spectrale est alors proposée, les paramètres étant là encore transmis par un canal auxiliaire à faible débit.La seconde partie de ce document est consacrée à l'intégration du tatouage audio dans les techniques de renforcement de la qualité des signaux audio précitées. Dans ce contexte, le tatouage audio remplace le canal auxiliaire précédent et œuvre comme une mémoire du signal originel, porteuse d'informations nécessaires pour la correction d'harmonicité et la réduction de pré-écho. Cette seconde partie a été précédée par une étape approfondie de l'évaluation des performances de la technique de tatouage adoptée en terme de robustesse à la compression MPEG (MP3, AAC et aacPlus).

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