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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.
1

Implementations of a Merging Mechanism for Multiple Video Surveillances in TCP Networks

Sung, Yi-Cheng 11 July 2012 (has links)
This thesis proposes a merging mechanism for multiple video surveillances in TCP networks. Merging video streams not only can benefit network administration but also reduce the waste of bandwidth. In this thesis, we design a Video-Merging Gateway (VMG) between cameras and control center to merge two video streams transmitted from cameras and received by control center. In the merging mechanism, we develop two modes: Interleave and Overlay. Interleave mode includes two operation types: Single Frame and Proportional. The former merges video streams by interleaving frames one by one from two cameras, and the latter merges video streams according to an FPS (frame per second) ratio between two cameras. Overlay mode vertically displays two video streams in separate frames on the web browser. We implement VMG on a Linux platform. In the interleave mode, we recalculate both the sequence number and the Ack number of a video packet, and create Ack packet for dropped frames while merging two TCP video streams. In the overlay mode, we modify the decoding messages in the frames and separate data between two video streams to avoid decoding errors. Finally, we analyze the complexity of merging algorithms. By carefully determining the timing for responding the created Ack based on Retransmission Time Out (RTO), packet retransmition can be avoided. In addition, we found out that the number of instructions to execute the algorithm is increased by multiple integers along with the picture sizes under interleave mode. As for overlay mode, the number of instructions is increased linearly along with the payload length and the total amount of data and Ack packets.
2

Rozhraní pro senzory PHpix / PHpix interface board

Opioł, Zbigniew January 2021 (has links)
This work investigates the interface and properties of an ionization radiation detector with the PhPix chip, which is the basis of a future large-scale detector for use in nuclear medicine. In the next stage, an IP core for communication between the processor system and the PhPix chips on the Zynq platform is designed. Furthermore, software for video transmission over Ethernet interface is developed.
3

Effect of additional compression features on h.264 surveillance video

Comstedt, Erik January 2017 (has links)
In video surveillance business, a recurring topic of discussion is quality versus data usage. A higher quality allows for more details to be captured at the cost of a higher bit rate, and for cameras monitoring events 24 hours a day, limiting data usage can quickly become a factor to consider. The purpose of this thesis has been to apply additional compression features to a h.264 video steam, and evaluate their effects on the videos overall quality. Using a surveillance camera, recordings of video streams were obtained. These recordings had constant GOP and frame rates. By breaking down one of these videos to an image sequence, it was possible to encode the image sequence into video streams with variable GOP/FPS using the software Ffmpeg. Additionally a user test was performed on these video streams, following the DSCQS standard from the ITU-R recom- mendation. The participants had to subjectively determine the quality of video streams. The results from the these tests showed that the participants did not no- tice any considerable difference in quality between the normal videos and the videos with variable GOP/FPS. Based of these results, the thesis has shown that that additional compression features can be applied to h.264 surveillance streams, without having a substantial effect on the video streams overall quality.
4

High quality video streaming with SCTP over CDMA2000 : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in the University of Canterbury /

Begg, C. Lee January 2007 (has links)
Thesis (M. Sc.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (p. 105-108). Also available via the World Wide Web.
5

Multimediální služby v bezdrátových sítích / Multimedia services in wireless networks

Bučina, Peter January 2012 (has links)
The main topic of my diploma thesis is dedicated to the issue of wireless networks mostly aimed at IEEE 802.11 standard. Theoretical part of the thesis is divided into three main chapters. It deals with basic overview of standards, architecture, utilization of radio spectrum and modulating techniques in signal processing. Further, it describes basic security measures and quality of service requirements in WLAN networks. The thesis is complemented by two separate laboratory assignments focused on procedure related to the chosen problematic. The first assignment handles common steps to break ciphered protocols WEP and WPA in WLAN’s. Linux software called Back Track 5 was used to provide complete package of tools for WLAN security tests. The second one is aimed at practical options on video streaming in converged wireless networks and also at remote access of mobile users to wireless IP camera video stream.
6

Efficient Fpga Implementation Of Image Enhancement Using Video Streams

Gunay, Hazan 01 January 2010 (has links) (PDF)
This thesis is composed of three main parts / displaying an analog composite video input by via converting to digital VGA format, license plate localization on a video image and image enhancement on FPGA. Analog composite video input, either PAL or NTSC is decoded on a video decoder board / then on FPGA, video data is converted from 4:2:2 YCbCr format to RGB. To display RGB data on the screen, line doubling de-interlacing algorithm is used since it is efficient considering computational complexity and timing. When taking timing efficiency into account, image enhancement is applied only to beneficial part of the image. In this thesis work, beneficial part of the image is considered as numbered plates. Before image enhancement process, the location of the plate on the image must be found. In order to find the location of plate, a successful method, edge finding is used. It is based on the idea that the plate is found on the rows, where the brightness variation is largest. Because of its fast execution, band-pass filtering with finite response (FIR) is used for highlighting the high contrast areas. Image enhancement with rank order filter method is chosen to remove the noise on the image. Median filter, a rank order filter, is designed and simulated. To improve image quality while reducing the process time, the filter is applied only to the part of the image where the plate is. Design and simulation is done using hardware design language VHDL. Implementations of the chosen approaches are done on MATLAB and Xilinx Virtex-2 Pro FPGA. Improvement of the implementation considering speed and area is evaluated.
7

Scene Understanding For Real Time Processing Of Queries Over Big Data Streaming Video

Aved, Alexander 01 January 2013 (has links)
With heightened security concerns across the globe and the increasing need to monitor, preserve and protect infrastructure and public spaces to ensure proper operation, quality assurance and safety, numerous video cameras have been deployed. Accordingly, they also need to be monitored effectively and efficiently. However, relying on human operators to constantly monitor all the video streams is not scalable or cost effective. Humans can become subjective, fatigued, even exhibit bias and it is difficult to maintain high levels of vigilance when capturing, searching and recognizing events that occur infrequently or in isolation. These limitations are addressed in the Live Video Database Management System (LVDBMS), a framework for managing and processing live motion imagery data. It enables rapid development of video surveillance software much like traditional database applications are developed today. Such developed video stream processing applications and ad hoc queries are able to "reuse" advanced image processing techniques that have been developed. This results in lower software development and maintenance costs. Furthermore, the LVDBMS can be intensively tested to ensure consistent quality across all associated video database applications. Its intrinsic privacy framework facilitates a formalized approach to the specification and enforcement of verifiable privacy policies. This is an important step towards enabling a general privacy certification for video surveillance systems by leveraging a standardized privacy specification language. With the potential to impact many important fields ranging from security and assembly line monitoring to wildlife studies and the environment, the broader impact of this work is clear. The privacy framework protects the general public from abusive use of surveillance technology; iii success in addressing the "trust" issue will enable many new surveillance-related applications. Although this research focuses on video surveillance, the proposed framework has the potential to support many video-based analytical applications.
8

Free Viewpoint TV

Hussain, Mudassar January 2010 (has links)
This thesis work regards free viewpoint TV. The main idea is that users can switch between multiple streams in order to find views of their own choice. The purpose is to provide fast switching between the streams, so that users experience less delay while view switching. In this thesis work we will discuss different video stream switching methods in detail. Then we will discuss issues related to those stream switching methods, including transmission and switching. We shall also discuss different scenarios for fast stream switching in order to make services more interactive by minimizing delays. Stream switching time varies from live to recorded events. Quality of service (QoS) is another factor to consider which can be improved by assigning priorities to the packets. We will discuss simultaneous stream transmission methods which are based on predictions and reduced quality streams for providing fast switching. We will present prediction algorithm for viewpoint prediction, propose system model for fast viewpoint switching and make evaluation of simultaneous stream transmission methods for free viewpoint TV. Finally, we draw our conclusions and propose future work. / Degree project
9

Zpracování obrazu v systému Android - detekce a rozpoznání obličeje / Image processing using Android device

Korchakov, Sergei January 2014 (has links)
This master’s Thesis focuses on image processing on Android platform and development of an application, that is able to do face detection and recognition in real scene. Thesis gives highlight of modern algorithms of face detection. It first examines and compares the standard features of Android platform (FaceDetector a FaceDetectionListener) and JJIL, OpenIMAJ, OpenCV libraries experiment, and presents the results. For purposes of face recognition was selected OpenCV library. Three different algorithms of identification were tested: FisherFaces, EigenFaces a Local Binary Patterns Histograms. Based on performance comparison best methods were implemented in developed application.

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