El presente trabajo de tesis tiene como objetivo principal el desarrollo de un algoritmo de estabilización de video robusto y eficiente frente a cambios de escala, rotación e iluminación. La estabilización de video es una etapa de pre procesamiento utilizada para eliminar o reducir el ruido que se adhiere debido a movimientos involuntarios en los videos. Su importancia radica en que procesamientos posteriores requieren de imágenes alineadas y libres de distorsión espacial. El documento está divido en cuatro capítulos descritos a continuación: En el capítulo 1 se presenta la problemática de la estabilización de videos así como las aplicaciones en diversos campos. Se explicará cómo los videos pueden ser afectados por factores ajenos a la cámara. Entre las aplicaciones se mencionarán procesamientos posteriores que requieren estabilización como paso previo y aplicaciones finales en temas de seguridad, industria y entretenimiento. En el capítulo 2 se mencionan las alternativas de solución del problema. Se presentan tanto las alternativas como sus características, ventajas y desventajas. Entre ellas se describen algunas alternativas mecánicas, que involucran equipos y sistemas sofisticados, y alternativas digitales como registro de imágenes, Structure from Motion y Geometría Epipolar. El capítulo 3 describe la metodología a emplear. Se utilizan gráficas, diagramas e imágenes para mostrar de manera sencilla cómo se piensa atacar el problema. Se describen los parámetros utilizados en cada etapa. El capítulo 4 muestra las simulaciones y los resultados del algoritmo implementado. Mediante imágenes se muestra los resultados de las etapas descritas en el capítulo anterior / Tesis

Video streaming has become increasingly popular with commercial video streaming applications such as YouTube accounting for a large quantity of Internet traffic. While streaming video is sensitive to bandwidth jitter, a receiver buffer can ameliorate the effects of jitter by adjusting to the difference between the transmission rate and the playback rate. Unfortunately, there are few studies to determine the best size of the receiver buffer for TCP streaming. In this work, we investigate how the buffer size of video streaming applications changes with respect to variation in bandwidth. We model the video streaming system over TCP using simulation to develop our buffering algorithm. We propose using a dynamic client buffer size based on measured bandwidth variation to achieve fewer interruptions in video streaming playback. To evaluate our approach, we implement an application to run experiments comparing our algorithm with the buffer size of commercial video streaming.

Thesis (M.S.V.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1982. / MICROFICHE COPY AVAIALABLE IN ARCHIVES AND ROTCH. / Bibliography: leaf 20. / by Louis Joseph Massiah. / M.S.V.S.

This dissertation examines early adopters of mass-marketed Virtual Reality (VR), as well as other immersive technologies, and the playful processes by which they incorporate the devices into their lives within New York City. Starting in 2016, relatively inexpensive head-mounted displays (HMDs) began to be manufactured and distributed by leaders in the game and information technology industries. However, even before these releases, developers and content creators were testing the devices through “development kits.” These de facto early adopters, who are distinctly commercially-oriented, acted as a launching point for the dissertation to scrutinize how, why and in what ways digital technologies spread to the wider public. Taking a multimethod approach that combines semi-structured interviews, two years of participant observation, media discourse analysis and autoethnography, the dissertation details a moment in the diffusion of an innovation and how publicity, social forces and industry influence adoption. This includes studying the media ecosystem which promotes and sustains VR, the role of New York City in framing opportunities and barriers for new users, and a description of meetups as important communities where devotees congregate. With Game Studies as a backdrop for analysis, the dissertation posits that the blurry relationship between labor and play held by most enthusiasts sustains the process of VR adoption. Their “playbor” colors not only the rhetoric and the focus of meetups, but also the activities, designs, and, most importantly, the financial and personal expenditures they put forth. Ultimately, play shapes the system of production by which adopters of commercial VR are introduced to the technology and, eventually, weave it into their lives. Situating play at the center of this system highlights that the assimilation of digital media is in part an embodied and irrational experience. It also suggests new models by which future innovations will spread to the public.

by Siu Wah Lau. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (p. 146-153). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

As a proof of concept, the presented power-efficient design methodology is experimentally verified on a H.264/AVC baseline decoding system. A prototype chip is fabricated in UMC 0.18mum 1P6M standard CMOS technology. It is capable to decode H.264/AVC baseline profile of QCIF at 30fps. The chip contains 169k gates and 2.5k bytes on-chip SRAM with 4.5mmx4.5mm chip area. It dissipates 293muW at 1.0V and 973muW at 1.8V during realtime video decoding. Compared with conventional designs, the measured power consumption is reduced up to one order of magnitude. / CMOS technology has now entered "power-limited scaling regime", where power consumption moves from being one of many design metrics to being the number one design metric. However, rapid advances of multimedia entertainment pose more stringent constraints on power dissipation mainly due to the increased video quality. Although general power-efficient design techniques have been formed for several years, no literature studied how to systematically apply them on a specific application like video decoding. Besides these general methods, video decoding has its unique power optimization entries due to temporal, spatial, and statistical redundancy in digital video data. / This research focuses on a systematic way to exploit power saving potentials spanning all design levels for real-time video decoding. At the algorithm level, the computational complexity and data width are optimized. At the architectural level, pipelining and parallelism are widely adopted to reduce the operating frequency; distributed processing greatly helps to reduce the number of global communications; hierarchical memory organization moves great part of data access from larger or external memories to smaller ones. At the circuit level, resource sharing reduces total switching capacitance by multi-function reconfigurations; the knowledge about signal statistics is exploited to reduce the number of transitions; data dependent signal-gating and clock-gating are introduced which are dynamic techniques to for power reduction; multiplications, which account for large chip area and switching power, are reduced to minimum through proper transformations, while complex dividers are totally eliminated. At the transistor and physical design level, cell sizing and layout are optimized for power-efficiency purpose. The higher levels, like algorithm and architecture, contribute to larger portion of power reduction, while the lower levels, like transistor and physical, further reduce power where high level techniques are not applicable. / Xu, Ke. / "September 2007." / Adviser: Chui-Sing Choy. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4952. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 239-247). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

A steganographic method was developed based on the temporal redundancies present in digital video streams, these redundancies are utilised by the H.264 encoding standard to reduce the bandwidth requirements of a digital video stream while maintaining content quality. The temporal redundancies are used to steganographically embed unique binary data within the digital video stream, this results in a unique embedding strategy within each video stream while also utilising areas that reduce the potential data loss experienced during the H.264 encoding process. The effectivness of the developed steganographic method is measured using the common steganographic metrics of Payload Capacity, Embedded Data Robustness and Media Impact. The results illustrate that the compensation of mutative factors in the embedding process using temporal redundancies result in a more robust method of data embedding within digital video encoded using H.264.

Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores (Major Telecomunicação). Faculdade de Engenharia. Universidade do Porto. 2010

Abstract not available

A controlled laboratory experiment was undertaken to simulate varying swash zone characteristics and sensor-target geometry found in digital images collected by ARGUS coastal imaging systems. Using a hyperspectral sensor, reflectance data were integrated over the respective red, blue and green wavelengths corresponding to a standard ARGUS video imaging sensor. The dominant swash zone parameters affecting shoreline detection were found to be the presence or absence of surface foam, site-specific sediment characteristics (especially colour), and water depth. Winter versus summer solar elevation and the sensor zenith were also found to affect the cross-shore location of the detected waterline. With this new information, site- and time-specific corrections can be applied to coastal digital imagery, to improve the confidence of shoreline detection.