<p>This thesis explores the possibilities of avoiding the issues generally associated with compression of noisy imagery, through the usage of vector quantization. By utilizing the learning aspects of vector quantization, image processing operations such as noise reduction could be implemented in a straightforward way. Several techniques are presented and evaluated. A direct comparison shows that for noisy imagery, vector quantization, in spite of it's simplicity, has clear advantages over MPEG-4 encoding.</p>

<p>In this thesis work a part of the video coding standard H.264 has been implemented. The part of the video coder that is used to code the I-frames has been implemented to see how well suited it is for regular image coding. The big difference versus other image coding standards, such as JPEG and JPEG2000, is that this video coder uses both a predictor and a transform to compress the I-frames, while JPEG and JPEG2000 only use a transform. Since the prediction error is sent instead of the actual pixel values, a lot of the values are zero or close to zero before the transformation and quantization. The method is much like a video encoder but the difference is that blocks of an image are predicted instead of frames in a video sequence.</p> / <p>I det här examensarbetet har en del av videokodningsstandarden H.264 implementerats. Den del av videokodaren som används för att koda s.k. I-bilder har implementerats för att testa hur bra den fungerar för ren stillbildskodning. Den stora skillnaden mot andra stillbildskodningsmetoder, såsom JPEG och JPEG2000, är att denna videokodaren använder både en prediktor och en transform för att komprimera stillbilderna, till skillnad från JPEG och JPEG2000 som bara använder en transform. Eftersom prediktionsfelen skickas istället för själva pixelvärdena så är många värden lika med noll eller nära noll redan innan transformationen och kvantiseringen. Metoden liknar alltså till mycket en ren videokodare, med skillnaden att man predikterar block i en bild istället för bilder i en videosekvens.</p>

The purpose of this thesis is to present an attractive service for the third generation mobile network that includes streaming video. A prototype application for this service is to be built. The technique behind streaming video is to be presented so that it comes clear what kind of problems and solutions that are associated with streaming. Finally, a platform for streaming video is to be tested and evaluated through different channels. The attractive service presented in this thesis is MMS - Multimedia Messaging Service. Today's popular SMS is evolving beyond text to multimedia. Multimedia will be part of the next generation messaging service called MMS, which will, in an advanced shape, include streaming video. MMS is expected to be a successful service for the next generation?s cell phones. The WAP Forum and the 3GPP industry groups are responsible for standardizing MMS. The standard defines an MMS architecture, which has a number of key elements that interact with each other. The prototype application that was built is called mVideo Messaging and is an MMS that is built on the basis of the MMS standard. The kernel of the prototype is a platform from PacketVideo that makes it possible to stream video over wireless networks. Theories and tests makes it clear that the parameters affecting the video quality can be found at the source/target while coding and compressing, as well as at the streaming-channel. At the channel there are above all three network problems - packet loss, end-to-end delay and delay jitter. To deal with these matters, new protocols have been developed. At the source/target it is important use an efficient compression scheme. MPEG-4 is a new compression scheme that suits very well for streaming video through wireless channels. MPEG- 4 make use of scalability, is object oriented, and is optimized for streaming between 9,6 kbps and 4 Mbps. The service proposed in this thesis as a future service for 3G is practicable. It is also shown that the service can be built using the technology of today.

At Saab Aerosystems, situated in Linköping Sweden, there is a presentation and manoeuvre simulator simulating the fighter jet JAS-39 Gripen. This flight simulator is called PMSIM. In this thesis we study how to transfer sensor images generated by PMSIM to other simulators or desktop computers. The transmission is band-limited so some kind of image coding must be used. Because of this the greater part of this thesis is concerned with image coding. To fulfill the real time requirement the image coding has to be quite simple and the transmission has to be fast. To achieve fast transmission the network protocol has to use as little overhead information as possible. Such a protocol has therefore been designed and implemented. This report also includes a survey about real radio links. This survey investigates how the quality of the video stream can be affected by noise and other disturbing elements. The work in this report revolves around the implementation of a video link. The purpose of this link is to transmit and display sensor images. The link consists mainly of the three following parts: image coder, network link and image player. The image coding has been focused on MPEG and wavelets. The wavelet technique is not a well known coding principle for video applications. Although as a coding technique for still images the technique is well known. For instance it is used in the JPEG2000-standard. Experiments conducted and published in this report suggest that for some applications the wavelet technique can be a viable candidate, with respect to the MPEG technique, for a video coder.

This thesis explores the possibilities of avoiding the issues generally associated with compression of noisy imagery, through the usage of vector quantization. By utilizing the learning aspects of vector quantization, image processing operations such as noise reduction could be implemented in a straightforward way. Several techniques are presented and evaluated. A direct comparison shows that for noisy imagery, vector quantization, in spite of it's simplicity, has clear advantages over MPEG-4 encoding.

<p>The purpose of this thesis is to present an attractive service for the third generation mobile network that includes streaming video. A prototype application for this service is to be built. The technique behind streaming video is to be presented so that it comes clear what kind of problems and solutions that are associated with streaming. Finally, a platform for streaming video is to be tested and evaluated through different channels. </p><p>The attractive service presented in this thesis is MMS - Multimedia Messaging Service. Today's popular SMS is evolving beyond text to multimedia. Multimedia will be part of the next generation messaging service called MMS, which will, in an advanced shape, include streaming video. MMS is expected to be a successful service for the next generation?s cell phones. </p><p>The WAP Forum and the 3GPP industry groups are responsible for standardizing MMS. The standard defines an MMS architecture, which has a number of key elements that interact with each other. The prototype application that was built is called mVideo Messaging and is an MMS that is built on the basis of the MMS standard. The kernel of the prototype is a platform from PacketVideo that makes it possible to stream video over wireless networks. </p><p>Theories and tests makes it clear that the parameters affecting the video quality can be found at the source/target while coding and compressing, as well as at the streaming-channel. At the channel there are above all three network problems - packet loss, end-to-end delay and delay jitter. To deal with these matters, new protocols have been developed. At the source/target it is important use an efficient compression scheme. MPEG-4 is a new compression scheme that suits very well for streaming video through wireless channels. MPEG- 4 make use of scalability, is object oriented, and is optimized for streaming between 9,6 kbps and 4 Mbps. </p><p>The service proposed in this thesis as a future service for 3G is practicable. It is also shown that the service can be built using the technology of today.</p>

Title from PDF of title page. / Document formatted into pages; contains 82 pages. / Thesis (M.S.E.E.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Image quality measures are used to optimize image processing algorithms and evaluate their performances. The only reliable way to assess image quality is subjective evaluation by human observers, where the mean value of their scores is used as the quality measure. This is known as mean opinion score (MOS). In addition to this measure there are various objective (quantitative) measures. Most widely used quantitative measures are: mean squared error (MSE), peak signal to noise ratio (PSNR) and signal to noise ratio (SNR). Since these simple measures do not always produce results that are in agreement with subjective evaluation, many other quality measures have been proposed. They are mostly various modifications of MSE, which try to take into account some properties of human visual system (HVS) such as nonlinear character of brightness perception, contrast sensitivity function (CSF) and texture masking. / ABSTRACT: In these approaches quality measure is computed as MSE of input image intensities or frequency domain coefficients obtained after some transform (DFT, DCT etc.), weighted by some coefficients which account for the mentioned properties of HVS. These measures have some advantages over MSE, but their ability to predict image quality is still limited. A different approach is presented here. Quality measure proposed here uses simple model of HVS, which has one user-defined parameter, whose value depends on the reference image. This quality measure is based on the average value of locally computed correlation coefficients. This takes into account structural similarity between original and distorted images, which cannot be measured by MSE or any kind of weighted MSE. The proposed measure also differentiates between random and signal dependant distortion, because these two have different effect on human observer. / ABSTRACT: This is achieved by computing the average correlation coefficient between reference image and error image. Performance of the proposed quality measure is illustrated by examples involving images with different types of degradation. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.

Thesis (M.F.A.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 58-61).

Thesis (Ph. D.)--University of Texas at El Paso, 2007. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M.Eng. (Electrical, Electromic and Computer Engineering)) -- University of Pretoria, 2007. / Includes bibliographical references (leaves 82-87)