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It is an educational escape room on math. For teenagers aged 15 and 16., Es un escape room educativo sobre las matemáticas. Para adolescentes de 15 y 16 años., Es un escape room educatiu per adolescents de 15 y 16 anys.

Security of secret data is major concern in today’s digitized world. It is an important task to preserve the secret data from the probable threats, during the transmission. Various techniques [1,2,3,4,5,6] have been proposed in literature for secure transmission of data but not much work has been done on the secret transmission of images which is one of the difficult task to accomplish. One of the secret sharing schemes [11,7] which are used in literature to share the image transmission side can be applied either by using Blakeley's secret sharing scheme [2]) or Shamir's scheme [1] for sharing a secret. In this paper Shamir’s secret sharing scheme is analyzed and implemented on a fingerprint biometric trait. The motivation for secret sharing [1,2] comes from the concept of secure key management. The schemes allow a user to divide portions of a secret among a participants group. Any t or more participants from a participants group of n members can cooperate to regain the original secret while (t-1) or fewer participants cannot reveal anything about the original secret.

Security of secret data is major concern in today’s digitized world. It is an important task to preserve the secret data from the probable threats, during the transmission. Various techniques [1,2,3,4,5,6] have been proposed in literature for secure transmission of data but not much work has been done on the secret transmission of images which is one of the difficult task to accomplish. One of the secret sharing schemes [11,7] which are used in literature to share the image transmission side can be applied either by using Blakeley's secret sharing scheme [2]) or Shamir's scheme [1] for sharing a secret. In this paper Shamir’s secret sharing scheme is analyzed and implemented on a fingerprint biometric trait. The motivation for secret sharing [1,2] comes from the concept of secure key management. The schemes allow a user to divide portions of a secret among a participants group. Any t or more participants from a participants group of n members can cooperate to regain the original secret while (t-1) or fewer participants cannot reveal anything about the original secret.

Security of secret data is major concern in today’s digitized world. It is an important task to preserve the secret data from the probable threats, during the transmission. Various techniques [1,2,3,4,5,6] have been proposed in literature for secure transmission of data but not much work has been done on the secret transmission of images which is one of the difficult task to accomplish. One of the secret sharing schemes [11,7] which are used in literature to share the image transmission side can be applied either by using Blakeley's secret sharing scheme [2]) or Shamir's scheme [1] for sharing a secret. In this paper Shamir’s secret sharing scheme is analyzed and implemented on a fingerprint biometric trait. The motivation for secret sharing [1,2] comes from the concept of secure key management. The schemes allow a user to divide portions of a secret among a participants group. Any t or more participants from a participants group of n members can cooperate to regain the original secret while (t-1) or fewer participants cannot reveal anything about the original secret.

Security of secret data is major concern in today’s digitized world. It is an important task to preserve the secret data from the probable threats, during the transmission. Various techniques [1,2,3,4,5,6] have been proposed in literature for secure transmission of data but not much work has been done on the secret transmission of images which is one of the difficult task to accomplish. One of the secret sharing schemes [11,7] which are used in literature to share the image transmission side can be applied either by using Blakeley's secret sharing scheme [2]) or Shamir's scheme [1] for sharing a secret. In this paper Shamir’s secret sharing scheme is analyzed and implemented on a fingerprint biometric trait. The motivation for secret sharing [1,2] comes from the concept of secure key management. The schemes allow a user to divide portions of a secret among a participants group. Any t or more participants from a participants group of n members can cooperate to regain the original secret while (t-1) or fewer participants cannot reveal anything about the original secret.

Security of secret data is major concern in today’s digitized world. It is an important task to preserve the secret data from the probable threats, during the transmission. Various techniques [1,2,3,4,5,6] have been proposed in literature for secure transmission of data but not much work has been done on the secret transmission of images which is one of the difficult task to accomplish. One of the secret sharing schemes [11,7] which are used in literature to share the image transmission side can be applied either by using Blakeley's secret sharing scheme [2]) or Shamir's scheme [1] for sharing a secret. In this paper Shamir’s secret sharing scheme is analyzed and implemented on a fingerprint biometric trait. The motivation for secret sharing [1,2] comes from the concept of secure key management. The schemes allow a user to divide portions of a secret among a participants group. Any t or more participants from a participants group of n members can cooperate to regain the original secret while (t-1) or fewer participants cannot reveal anything about the original secret.

Security of secret data is major concern in today’s digitized world. It is an important task to preserve the secret data from the probable threats, during the transmission. Various techniques [1,2,3,4,5,6] have been proposed in literature for secure transmission of data but not much work has been done on the secret transmission of images which is one of the difficult task to accomplish. One of the secret sharing schemes [11,7] which are used in literature to share the image transmission side can be applied either by using Blakeley's secret sharing scheme [2]) or Shamir's scheme [1] for sharing a secret. In this paper Shamir’s secret sharing scheme is analyzed and implemented on a fingerprint biometric trait. The motivation for secret sharing [1,2] comes from the concept of secure key management. The schemes allow a user to divide portions of a secret among a participants group. Any t or more participants from a participants group of n members can cooperate to regain the original secret while (t-1) or fewer participants cannot reveal anything about the original secret.

This work explores the reference-based talking face video super-resolution for video conferencing even under low bandwidth network conditions. Our objective is to reconstruct high-quality talking face video with given low-resolution video and sparsely given high-resolution frames for every ten frames. To this end, our method utilizes the pretrained GANs as priors knowledge to reconstruct photo-realistic face images. Using GANs pretrained on a large dataset is much helpful to generate plausible face images even with the low-resolution images; however, it shows low fidelity. It means that the person's face identity between original and reconstructed ones is quite different. To tackle this problem, our method is designed to exploit the high-resolution feature which can help generate high-fidelity face images. The proposed method exploits the recent development of reference-based super-resolution techniques and generative priors. We aggregate these two approaches into a single framework. Experimental results show that the proposed method can generate high-fidelity talking face video when more reference frames are given.

Security of secret data is major concern in today’s digitized world. It is an important task to preserve the secret data from the probable threats, during the transmission. Various techniques [1,2,3,4,5,6] have been proposed in literature for secure transmission of data but not much work has been done on the secret transmission of images which is one of the difficult task to accomplish. One of the secret sharing schemes [11,7] which are used in literature to share the image transmission side can be applied either by using Blakeley's secret sharing scheme [2]) or Shamir's scheme [1] for sharing a secret. In this paper Shamir’s secret sharing scheme is analyzed and implemented on a fingerprint biometric trait. The motivation for secret sharing [1,2] comes from the concept of secure key management. The schemes allow a user to divide portions of a secret among a participants group. Any t or more participants from a participants group of n members can cooperate to regain the original secret while (t-1) or fewer participants cannot reveal anything about the original secret.

En aquest projecte final de màster s’ha muntat i adaptat un dron per a que pugui adquirir imatge aèries i les envií de manera automatitzada a una unitat terrestre remota, que implementa un servidor web. Dintre del àmbit de la agricultura s’ha realitzat un assemblatge complert d’un dron quadcòpter teledirigit amb capacitat de volar autònomament. En aquest document s’expliquen tots els passos necessaris per al muntatge i la configuració d’un dron quadcòpter així el desenvolupament d’un servidor web capaç de rebre les imatges enviades per la càmera embarcada al dron. La primera part del projecte inclou una visió general dels tipus de drons que s’utilitzen actualment, així com les aplicacions més rellevant en l’àmbit de l’agricultura. També es descriuen els components i tecnologies computacionals software i hardware per a la elecció dels elements que formaran part del dron. Seguidament es descriu tot el procés d’assemblatge, configuració i calibració del dron, a més del desenvolupament d’un servidor web. També s’inclou el funcionament dels scripts utilitzats, tant en la Raspberry que controla la càmera com la del servidor. Finalment, es mostren els resultats i conclusions finals a partir de les proves que s’han realitzat.

This work explores the reference-based talking face video super-resolution for video conferencing even under low bandwidth network conditions. Our objective is to reconstruct high-quality talking face video with given low-resolution video and sparsely given high-resolution frames for every ten frames. To this end, our method utilizes the pretrained GANs as priors knowledge to reconstruct photo-realistic face images. Using GANs pretrained on a large dataset is much helpful to generate plausible face images even with the low-resolution images; however, it shows low fidelity. It means that the person's face identity between original and reconstructed ones is quite different. To tackle this problem, our method is designed to exploit the high-resolution feature which can help generate high-fidelity face images. The proposed method exploits the recent development of reference-based super-resolution techniques and generative priors. We aggregate these two approaches into a single framework. Experimental results show that the proposed method can generate high-fidelity talking face video when more reference frames are given.

The RF spectrum is quite saturated. Light is alternative. At present a LED used for lighting can be modulated to achieve significant bit rates. The usage of VLC can be used also for providing communication and powering the IoT. Very simple devices can receive the light from a LED and can transmit to a camera. This approach is very convenient since one single camera can receive information from multiple devices in parallel., This project consists of designing and implementing a VLC system on raspberry and arduino platforms, low cost components. The light of the Raspberry Pi sends data to all devices, while the Arduinos can send data to the camera. That is, the camera can receive information from many devices in parallel. In this work, we have worked on the uplink of a full duplex VLC system. It is a prototype of wireless communication through visible light using a LED as a transmitting device and a digital camera as a receiver. It is designed to work indoors. The communication signal is transmitted as a sequence of ones and zeros that turn on or off the light source. A camera receives the signal when observing the presence or not of the point of light and converting it again in a binary signal. Image processing techniques are applied to calculate the signal received from the images., Este proyecto consiste en diseñar e implementar un sistema VLC en las plataformas de raspberry y arduino, componentes de bajo coste. La luz de la Raspberry Pi envía datos a todos los dispositivos, mientras que los Arduinos pueden enviar datos a la cámara. Es decir, la camara puede recibir información de muchos dispositivos en paralelo. En este trabajo, se ha trabajado en el uplink de un sistema VLC full duplex. Es un prototipo de comunicación inalámbrica a través de la luz visible utilizando un led como dispositivo transmisor y una cámara digital como receptor. Está diseñado para trabajar en interiores. La señal de comunicación se transmite como una secuencia de unos y ceros que encienden o apagan la fuente de luz. Una cámara recibe la señal al observar la presencia o no del punto de luz y convertirla nuevamente en una señal binaria. Se aplican técnicas de procesamiento de imágenes para calcular la señal recibida de las imágenes., Aquest projecte consisteix en dissenyar i implementar un sistema VLC a les plataformes de raspberry i arduino, components de baix cost. La llum de la Raspberry Pi envia dades a tots els dispositius, mentre que els Arduinos poden enviar dades a la càmera. És a dir, la càmera pot rebre informació de molts dispositius en paral·lel. En aquest treball, s'ha treballat en el uplink d'un sistema VLC full duplex. És un prototip de comunicació sense fils a través de la llum visible utilitzant un led com a dispositiu transmissor i una càmera digital com a receptor. Està dissenyat per treballar en interiors. El senyal de comunicació es transmet com una seqüència d'uns i zeros que encenen o apaguen la font de llum. Una càmera rep el senyal en observar la presència o no del punt de llum i convertir-la novament en un senyal binari. S'apliquen tècniques de processament d'imatges per calcular el senyal rebut de les imatges.

El objetivo principal es poder transmitir datos en tiempo real, en este caso enviaremos la información que captan unas cámaras (asignadas por la empresa VENCO), conectando todas las cámaras sobre una placa Raspberry pi del cual saldrá una única conexión que llegará hasta el ordenador, evitando que cause cualquier alteración sobre la información que estamos transmitiendo hasta que llegue a su destino.

The rapid advancement in wireless technologies and the reduced cost in electronic hardware has stimulated the vast deployment of Wireless Local Area Networks (WLANs) in public and residential places. Nowadays, a wide range of multimedia traffics emerge in WLANs with different Quality of Service (QoS) requirements. In order to support multimedia traffics with stringent requirements, IEEE 802.11e introduced HCF Controlled Channel Access (HCCA). In HCCA, Transmission Opportunity (TXOP) duration is allocated to the QoSenabled Station (QSTA) based on the mean characteristics of its Traffic Stream (TS) described by a TS Specification (TSPEC). Although HCCA operates well for the Constant Bit Rate (CBR) traffics, it is inadequate for Variable Bit Rate (VBR) traffic, where the instantaneous sending rate and the packet size are usually different from its mean values. The aim of this research is to address the deficiency of HCCA in supporting VBR video transmission over wireless networks. Accordingly, a novel polling scheme called Feasible Polling (F-Poll) is proposed to minimize the delay imposed by overpolling stations in the HCCA function. The actual arrival time of the next frame of the uplink TS is obtained and reported to the central scheduler called Hybrid Coordinator (HC). Upon the reception of the data frame at the HC, a decision will be made to poll the corresponding station in the next Service Interval (SI) or not to prevent stations that are not ready to transmit from receiving unnecessary polls. Consequently, the packet access delay and the channel utilization will be enhanced. The TXOP in HCCA scheduler is allocated to the QSTA based on its TSPEC by estimating the amount of data expected to be transmitted by the QSTA during the service interval. Yet, this estimation is not accurate for VBR traffics. Thus, a novel TXOP assignment scheme is proposed which is referred to as Adaptive TXOP Scheme (ATXOP). In this scheme, the TXOP duration is adopted based on the feedb

The rapid advancement in wireless technologies and the reduced cost in electronic hardware has stimulated the vast deployment of Wireless Local Area Networks (WLANs) in public and residential places. Nowadays, a wide range of multimedia traffics emerge in WLANs with different Quality of Service (QoS) requirements. In order to support multimedia traffics with stringent requirements, IEEE 802.11e introduced HCF Controlled Channel Access (HCCA). In HCCA, Transmission Opportunity (TXOP) duration is allocated to the QoSenabled Station (QSTA) based on the mean characteristics of its Traffic Stream (TS) described by a TS Specification (TSPEC). Although HCCA operates well for the Constant Bit Rate (CBR) traffics, it is inadequate for Variable Bit Rate (VBR) traffic, where the instantaneous sending rate and the packet size are usually different from its mean values. The aim of this research is to address the deficiency of HCCA in supporting VBR video transmission over wireless networks. Accordingly, a novel polling scheme called Feasible Polling (F-Poll) is proposed to minimize the delay imposed by overpolling stations in the HCCA function. The actual arrival time of the next frame of the uplink TS is obtained and reported to the central scheduler called Hybrid Coordinator (HC). Upon the reception of the data frame at the HC, a decision will be made to poll the corresponding station in the next Service Interval (SI) or not to prevent stations that are not ready to transmit from receiving unnecessary polls. Consequently, the packet access delay and the channel utilization will be enhanced. The TXOP in HCCA scheduler is allocated to the QSTA based on its TSPEC by estimating the amount of data expected to be transmitted by the QSTA during the service interval. Yet, this estimation is not accurate for VBR traffics. Thus, a novel TXOP assignment scheme is proposed which is referred to as Adaptive TXOP Scheme (ATXOP). In this scheme, the TXOP duration is adopted based on the feedb

In the past year, we successfully demonstrated several phenomena related to light localization, light beam manipulation, and light signal routing in free-space as well as in optically-induced photonic bandgap structures, including elimination of transverse instability in stripe solitons by one-dimensional lattices, linear and nonlinear control of optical beams in optical periodic structures. In particular, we predicted and demonstrated a new class of nonconventional edge states in optically induced honey-comb lattices - an optical analog of graphene, which has been published in Nature Material and Physics Review Letters. Our work was reported in a number of news media as well as featured in PRL cover. We are happy to report that we have made significant progress in this funded project with already many scientific research papers published in top-rated refereed journals (See attached list of publications that acknowledged the support from AFOSR). In addition, several students have actively involved in this project, and close collaboration has been maintained with other principal investigators supported by AFOSR., The original document contains color images.

This article proposes a joint source-channel coding technique for two-dimensional (2D) binary Markov sources by using concatenated turbo block codes composed of two Bose, Chaudhuri, Hocquenghem (BCH) codes, of which output is followed by a rate-1 recursive systematic convolutional code. The source correlation of all rows and columns of the 2D source is well exploited by using a modified Bahl–Cocke–Jelinek–Raviv (BCJR) algorithm for the decoding of the BCH codes. Simulation results show that the proposed technique outperforms in terms of bit error rate the codes that exploits one-dimensional (1D) source correlation using the modified BCJR algorithm, and obviously the conventional system without source correlation exploitation. In order to further improve the performance, this article aims to make fine-tuning of the code parameters, given the source correlation property, that can achieve performance even closer to the theoretical limit than without the fine-tuning. Finally, results of image transmission simulations using two images, one having strong and the other weak 2D correlation, are presented to demonstrate the effectiveness of our proposed technique., identifier:https://dspace.jaist.ac.jp/dspace/handle/10119/11417

This article proposes a joint source-channel coding technique for two-dimensional (2D) binary Markov sources by using concatenated turbo block codes composed of two Bose, Chaudhuri, Hocquenghem (BCH) codes, of which output is followed by a rate-1 recursive systematic convolutional code. The source correlation of all rows and columns of the 2D source is well exploited by using a modified Bahl–Cocke–Jelinek–Raviv (BCJR) algorithm for the decoding of the BCH codes. Simulation results show that the proposed technique outperforms in terms of bit error rate the codes that exploits one-dimensional (1D) source correlation using the modified BCJR algorithm, and obviously the conventional system without source correlation exploitation. In order to further improve the performance, this article aims to make fine-tuning of the code parameters, given the source correlation property, that can achieve performance even closer to the theoretical limit than without the fine-tuning. Finally, results of image transmission simulations using two images, one having strong and the other weak 2D correlation, are presented to demonstrate the effectiveness of our proposed technique.

論文研究了圖像及技頻信號的去躁技術，共分為四部分。第一部分研究了用來改進編碼的圖像的主觀同客觀賞質量的方法，介紹了兩個有效的圖像后處理技術。第二部分研究了基於貝葉斯估計鋒的對高斯噪聲圖像的去噪方法。第三部分介紹了對編碼的視頻信號去噪的兩個方法，這些方法可作為視頻環路和后處理濾波器，從而改進視頻信號的編碼性能。第四部分介紹了圖像邊緣檢測技術，該技術可結合基於於邊緣的圖像處理設術來改進含噪圖像的主觀同客觀質量。, 第一部分，我們研究了一些用來改進編碼的圖像和視頻主觀同客觀質量的有效技術。採用基於塊的離散餘弦變換(DCT) 壓縮標準的圖像和視頻存在編碼效應。為了減少圖像的編碼效應，我們提出了一個基於綫性最小均值平方誤差(MMSE)標準的非局部Kuan (NLK) 濾波器。它被用來恢復量化后的DCT係數，然後我們提出了雙重量非局部Kuan (DNLK) 濾波器。這個DNLK濾波器用在過完備的DCTl係數，進一步形成了過完備雙重非局部Kuan (OCNLK) 濾波器。通過對一些使用測試用的量化表編碼的圖像， JPEG編碼的圖像的實驗，驗證了這兩种方法的有效性。, 第二部分，我們採用了貝葉斯估計器來估計原始的變換域係數。該方法是對非局部Kuan (NLK) 濾波器的改進，它採用了高斯尺度混合模型來考慮變換域係數的非高斯特性。除去非局部估計的均值后的殘差係數並不是高斯分佈，所以我們採用了高斯混合模型來表示表示這些殘差係數。實驗給果證明了它在圖像去噪應用上的有效性，以及比NLK 濾波器更好的性能。, 第三部分描述了用來改進視頻編碼性能的基於NLK 的方法。對於採用楨内/間預測和變換編碼的視頻而言，直接使用NLK濾波器將不能有效的去除編碼效應。我們分析了其中的原因，並提出了兩個視頻環路濾波器:基於四叉樹的NLK (QNLK) 濾波器和基於四叉樹的過完備NLK (QOCNLK) 濾波器。NLK 和過完備NLK濾波器用來恢復視頻殘差的量化係數。這些恢復后的係數進一步投射到所設計的量化約數集(QCS)裏。四叉樹技術用來進行自適應的濾波控制。實驗結果表明了相對于H.264/AVC HighProfile ，這些技術達到了可觀的比特率壓縮效率和視覺質量改善。我們同時也採用了QNLK和QOCNLK濾波器進行視頻后處理，並給出了實驗結果和分析。, 第四部分，我們研究了一個基於非下採樣小波，使用三維隱馬爾可伕模型(HMM)的邊緣檢測技術。 提出的模型不僅能捕獲不同尺度間小波係數的關係，而且考慮了尺度内係數的依賴性。一個計算有效的最大似然(ML) 估計算法用來計算該模型的參數，每一個係數對應的隱含狀態用最大后騐(MAP) 估計來求得。基於一些自然圖像的實驗給果用來評償該算法。對於含噪圖像，該算法可以同時提取邊緣和去除噪聲信號。另外，提出的該模型對於其它的圖像視頻處理任務也是一個潛在的多尺度統計模型工具。, The thesis investigates techniques to reduce noise in image and video signals.The investigation can be divided into four parts. The first part studies methods to improve the objective and subjective quality of coded images. The proposed two efficient image postprocessing techniques are presented. The second part investigates noise reduction of image signals corrupted by Gaussian noise and presents a denoising method based on Bayes estimator. The third part investigates noise reduction of coded videos by two different approaches. The approaches are used as video loop and postprocessing filters, in order to improve the coding performance of video signals. Finally, the fourth part investigates a new edge detection method that can provide an accurate detection of edges. The method can be used together with edge-based image processing techniques to improve objective and subjective quality of noisy images., In the first part, the technique to improve the subjective and objective quality of coded images are studied. Coding artifacts exist in images using block-based discrete cosine transform (DCT) compression standards. In order to reduce image coding artifacts, a non-local Kuan's (NLK) filter is proposed from the minimum mean-square-error (MMSE) criterion. It is used to restore quantized DCT coefficients. Then we propose the dual non-local Kuan's (DNLK) filter by applying the NLK filter in dual-layer. The DNLK filter is further extended to form the overcomplete dual non-local Kuan's (OCDNLK) filter by applying to the overcomplete DCT coefficients. Experimental results on coded images using test quantization tables and JPEG coded images show the effectiveness of the two methods., In the second part, we use a Bayes least square estimator to estimate the original transform coefficients optimally, from the Bayes perspective. It is an improved nonlocal Kuan's filter by considering non-Gaussian property of transform coefficients using Gaussian scale mixture model. The residual coefficients after subtracting non-local estimated means are not Gaussian distributed, so a Gaussian scale mixture model is employed to represent the residual coefficients. Experiments demonstrate its efficiency on image denoising and better performance than the NLK filter., In the third part, the proposed methods based on the NLK filter to improve video coding performance are studied. Direct application of the NLK filter on videos coded using intra/inter-frame prediction and transform coding cannot improve coding performance efficiently. We identify the causes of the problem and propose quadtree-based NLK (QNLK) loop filter and quadtree-based overcomplete NLK (QOCNLK) loop filter to solve the problem. NLK and overcomplete NLK loop filters are used to restore quantized residual transform coefficients. Restored coefficients are then projected onto designed quantization constraint sets (QCS). Quadtree-based signaling strategy is used for adaptive filtering control. Experimental results show that the proposed loop filtering techniques achieve significant bit rate saving and visual quality improvement compared with H.264 or advanced video coding (AVC) High Profile. We also provide the experimental results and analysis of postprocessing application using QNLK and QOCNLK filters., In the fourth part, a new edge detecting technique using 3-D Hidden Markov Model (HMM) based on the non-decimated wavelet is studied. The proposed model can not only capture the relationship of wavelet coefficients inter-scale, but also consider the intra-scale dependence. A computationally efficient maximum likelihood (ML) estimation algorithm is employed to compute parameters and the hidden state of each coefficient is revealed by maximum a posteriori (MAP) estimation. Experimental results of natural images are provided to evaluate the algorithm. For noisy images, the method can extract edges and remove noise simultaneously. The method can be used together with edge-based image processing techniques to improve subjective and objective quality of noisy images. In addition, the proposed model has the potential to be an efficient multi-scale statistical modeling tool for other image or video processing tasks., Detailed summary in vernacular field only., Zhang, Renqi., Thesis (Ph.D.)--Chinese University of Hong Kong, 2012., Includes bibliographical references (leaves 109-113)., Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web., also in Chinese., Dedication --- p.ii, Acknowledgments --- p.iii, p.viii, Publications --- p.x, Nomenclature --- p.xii, Contents --- p.xviii, List of Figures --- p.xxi, List o f Tables --- p.xxiii, Chapter 1 --- Introduction --- p.1, Chapter 1.1 --- Motivation and Objectives --- p.1, Chapter 1.2 --- Thesis Outline --- p.4, Chapter 2 --- Image/Video Coding Standard --- p.5, Chapter 2.1 --- Image Coding Standard JPEG --- p.5, Chapter 2.1.1 --- JPEG Codec --- p.6, Chapter 2.1.2 --- Block-based Discrete Cosine Transform (DCT) --- p.7, Chapter 2.1.3 --- Quant ization and Entropy Coding --- p.9, Chapter 2.1.4 --- Decoding --- p.11, Chapter 2.1.5 --- Effects of JPEG Compression --- p.12, Chapter 2.2 --- Video Coding Standard H.264/AVC --- p.12, Chapter 2.2.1 --- H.264 Codec --- p.14, Chapter 2.2.2 --- Inter Prediction --- p.15, Chapter 2.2.3 --- Intra Prediction --- p.15, Chapter 2.2.4 --- Transform and Quantization --- p.17, Chapter 2.2.5 --- Deblocking Filter --- p.19, Chapter 2.3 --- Conclusion --- p.21, Chapter 3 --- Image Postprocessing --- p.22, Chapter 3.1 --- Introduction --- p.22, Chapter 3.2 --- The Proposed Non-local KUAN's Filter in the DCT Domain --- p.24, Chapter 3.2.1 --- LMMSE Filter in the DCT Domain --- p.25, Chapter 3.2.2 --- The solution of the LMMSE Filter --- p.26, Chapter 3.2.3 --- Non-local Parameter Estimation --- p.29, Chapter 3.2.4 --- Investigation on Assumptions 1 and 2 --- p.29, Chapter 3.3 --- Image Postprocessing by the Dual Non-local Kuan's Filter --- p.34, Chapter 3.3.1 --- DNLK Filter --- p.35, Chapter 3.3.2 --- OCDNLK Filter --- p.36, Chapter 3.4 --- Experimental Results and Analysis --- p.37, Chapter 3.4.1 --- Experiments on Three Test Quantization Tables --- p.37, Chapter 3.4.2 --- Experiment al Setting --- p.38, Chapter 3.4.3 --- Experiment al Results and Comparison with State-of-the-Art Methods --- p.38, Chapter 3.4.4 --- Postprocessing on JPEG Coded Images --- p.40, Chapter 3.4.5 --- Complexity Analysis --- p.40, Chapter 3.5 --- Conclusion --- p.41, Chapter 4 --- Improved Non-local Kuan's Filter using a Gaussian Scale Mixture --- p.49, Chapter 4.1 --- Introduction --- p.49, Chapter 4.1 --- Non-local Kuan's filter in the DCT domain --- p.50, Chapter 4.1 --- Improved Non-local Kuan's Filter using a Guassian Scale Mixture --- p.52, Chapter 4.3.1 --- Gaussian Scale Mixture Model --- p.52, Chapter 4.3.2 --- Computation of Bayes Least Square Estimator --- p.55, Chapter 4.4 --- Experimental Sett ings and Results --- p.56, Chapter 4.5 --- Conclusion --- p.57, Chapter 5 --- Quadtree-based Non-local Kuan's Filtering in Video Compression --- p.59, Chapter 5.1 --- Introduction --- p.59, Chapter 5.2 --- The Proposed Loop Filters --- p.62, Chapter 5.2.1 --- Non-local Kuan's Filter --- p.62, Chapter 5.2.2 --- The NLK Loop Filter --- p.65, Chapter 5.2.3 --- The Overcomplete NLK Loop Filter --- p.67, Chapter 5.2.4 --- Use of t he Quant ization Constraint Set (QCS) --- p.69, Chapter 5.2.5 --- Performance of t he NLK and OCNLK Loop Filters for Video Coding --- p.70, Chapter 5.2.6 --- The Proposed Quadtree-based NLK and OCNLK Loop Filters --- p.74, Chapter 5.3 --- Experimental Result s and Analysis of QNLK and QOCNLK Loop Filters --- p.76, Chapter 5.3.1 --- Experiment al Results of QNLK and QOCNLK Loop Filters --- p.76, Chapter 5.3.2 --- Computational Complexity Analysis --- p.78, Chapter 5.4 --- QNLK and QOCNLK Postprocessing Filters --- p.82, Chapter 5.4.1 --- Experimental Result s and Analysis ofQNLK and QOCNLK Postprocessing Filters --- p.84, Chapter 5.5 --- Conclusion --- p.85, Chapter 6 --- Image Edge Detection using 3-D Hidden Markov Model based on the Non-decimated Wavelet --- p.88, Chapter 6.1 --- Introduction --- p.88, Chapter 6.2 --- Three-dimensional HMM based on the Non-decimated Wavelet (3-D N-WHMM) --- p.90, Chapter 6.2.1 --- Hidden Markov Model (HMM) --- p.90, Chapter 6.2.2 --- 3-D Hidden Markov Model (3-D HMM) --- p.91, Chapter 6.2.3 --- Construction of the 3-D NWHMM --- p.92, Chapter 6.2.4 --- Probabilistic Model for Individual Wavelet Coefficient --- p.92, Chapter 6.2.5 --- Training Paramet ers and Searching for Hidden States --- p.94, Chapter 6.3 --- Experimental Results and Analysis --- p.96, Chapter 6.3.1 --- The algorithm implementation --- p.96, Chapter 6.3.2 --- Comparisons with Canny and two multi-scalet echniques --- p.96, Chapter 6.3.3 --- Experimental results of noisy images --- p.98, Chapter 6.4 --- Conclusion --- p.98, Chapter 7 --- Conclusions and Future Work --- p.103, Chapter 7.1 --- Contributions of The Thesis --- p.103, Chapter 7.2 --- Future Work and Research Directions --- p.104, Chapter A --- Appendix A --- p.107, Chapter A.1 --- Mathematical Derivations of equation (4.6) --- p.107, Bibliography --- p.109, http://library.cuhk.edu.hk/record=b5549564, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Previous studies highlighted the importance of using residual redundancy techniques in the design of a joint source channel decoder for the case of data transmission over binary symmetrical channel. This paper uses the sequence maximum a posteriori (MAP) method, which is one of the residual redundancy techniques to design a joint source channel coding with the representation of the wireless communication channel by the Gilbert-Elliott channel (GEC). The paper also discusses the issue of parameters estimation for the GEC channel. A new modification is suggested to the Baum-Welch re-estimation technique in order to improve its performance and reduces its computational requirements., This paper presents the design of a joint source channel decoder using the sequence maximum a posteriori method, which is one of the residual redundancy techniques. The paper applies hidden Markov models to estimate the parameters of the Gilbert-Elliott channel model. A modified Baum-Welch algorithm is proposed where the estimation obtained from the direct method is taken as the initial estimates of the Baum-Welch algorithm, reducing time significantly. Details about non-stationary systems and signals can be found in the comprehensive book on Time-Frequency Signal Analysis and Processing (see http://www.elsevier.com/locate/isbn/0080443354). In addition, the most recent upgrade of the original software package that calculates Time-Frequency Distributions and Instantaneous Frequency estimators can be downloaded from the web site: www.time-frequency.net. This was the first software developed in the field, and it was first released publicly in 1987 at the 1st ISSPA conference held in Brisbane, Australia, and then continuously updated).

Implementació de càmera IP per Wi-Fi mitjançant dispositiu mòbil., [ANGLÈS] IP Camera implementation with Android SDK. It takes the images from the device cam and sends them through the Wi-Fi network using RTP., [CASTELLÀ] Implementación en Android SDK de cámara IP, que envía las imágenes captadas por el móvil a través de la red Wi-Fi mediante RTP., [CATALÀ] Implementació en Android SDK de càmera IP, que envia les imatges captades pel la càmera del mòbil en RTP a través de la xarxa Wi-Fi.

Besides ABT with higher order transform, a transform based template matching is also investigated. A fast method of template matching, called Fast Walsh Search, is developed. This search method has similar accuracy as exhaustive search but significantly lower computation requirement., In this thesis, the development of simple but efficient order-16 transforms will be shown. Analysis and comparison with existing order-16 transforms have been carried out. The proposed order-16 transforms were integrated to the existing coding standard reference software individually so as to achieve a new ABT system. In the proposed ABT system, order-4, order-8 and order-16 transforms coexist. The selection of the most appropriate transform is based on the rate-distortion performance of these transforms. A remarkable improvement in coding performance is shown in the experiment results. A significant bit rate reduction can be achieved with our proposed ABT system with both subjective and objective qualities remain unchanged., Prior knowledge of the coefficient distribution is a key to achieve better coding performance. This is very useful in many areas in coding such as rate control, rate distortion optimization, etc. It is also shown that coefficient distribution of predicted residue is closer to Cauchy distribution rather than traditionally expected Laplace distribution. This can effectively improve the existing processing techniques., Three kinds of order-l 6 orthogonal DCT-like integer transforms are proposed in this thesis. The first one is the simple integer transform, which is expanded from existing order-8 ICT. The second one is the hybrid integer transform from the Dyadic Weighted Walsh Transform (DWWT). It is shown that it has a better performance than simple integer transform. The last one is a recursive transform. Order-2N transform can be derived from order-N one. It is very close to the DCT. This recursive transform can be implemented in two different ways and they are denoted as LLMICT and CSFICT. They have excellent coding performance. These proposed transforms are investigated and are implemented into the reference software of H.264 and AVS. They are also compared with other order-16 orthogonal integer transform. Experimental results show that the proposed transforms give excellent coding performance and ease to compute., Transform is a very important coding tool in video coding. It decorrelates the pixel data and removes the redundancy among pixels so as to achieve compression. Traditionally, order-S transform is used in video and image coding. Latest video coding standards, such as H.264/AVC, adopt both order-4 and order-8 transforms. The adaptive use of more than one transforms of different sizes is known as Arbitrary Block-size Transform (ABT). Transforms other than order-4 and order-8 can also be used in ABT. It is expected larger transform size such as order-16 will benefit more in video sequences with higher resolutions such as nap and 1a8ap sequences. As a result, order-16 transform is introduced into ABT system., Fong, Chi Keung., Adviser: Wai Kuen Cham., Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: ., Thesis (Ph.D.)--Chinese University of Hong Kong, 2011., Includes bibliographical references., 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, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web., also in Chinese., isbn: 9781267099471, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

The transmission of high resolution raster images over low-bandwidth communication lines requires a great amount of time. User interaction in such a transmission environment can be frustrating. The problem can be eased somewhat by transmitting a series of low resolution approximations, which converge to the final image. Several methods of computing such a series of images are presented. Each is related to a particular type of pyramid data structure. They rely on the ability of the local display device to overpaint an existing image, and generally require some transmission and computation overhead. However, one of the methods requires no transmission overhead and only a small amount of local computation. A notation is introduced that permits concise descriptions of the image refinement processes.

Besides ABT with higher order transform, a transform based template matching is also investigated. A fast method of template matching, called Fast Walsh Search, is developed. This search method has similar accuracy as exhaustive search but significantly lower computation requirement., In this thesis, the development of simple but efficient order-16 transforms will be shown. Analysis and comparison with existing order-16 transforms have been carried out. The proposed order-16 transforms were integrated to the existing coding standard reference software individually so as to achieve a new ABT system. In the proposed ABT system, order-4, order-8 and order-16 transforms coexist. The selection of the most appropriate transform is based on the rate-distortion performance of these transforms. A remarkable improvement in coding performance is shown in the experiment results. A significant bit rate reduction can be achieved with our proposed ABT system with both subjective and objective qualities remain unchanged., Prior knowledge of the coefficient distribution is a key to achieve better coding performance. This is very useful in many areas in coding such as rate control, rate distortion optimization, etc. It is also shown that coefficient distribution of predicted residue is closer to Cauchy distribution rather than traditionally expected Laplace distribution. This can effectively improve the existing processing techniques., Three kinds of order-l 6 orthogonal DCT-like integer transforms are proposed in this thesis. The first one is the simple integer transform, which is expanded from existing order-8 ICT. The second one is the hybrid integer transform from the Dyadic Weighted Walsh Transform (DWWT). It is shown that it has a better performance than simple integer transform. The last one is a recursive transform. Order-2N transform can be derived from order-N one. It is very close to the DCT. This recursive transform can be implemented in two different ways and they are denoted as LLMICT and CSFICT. They have excellent coding performance. These proposed transforms are investigated and are implemented into the reference software of H.264 and AVS. They are also compared with other order-16 orthogonal integer transform. Experimental results show that the proposed transforms give excellent coding performance and ease to compute., Transform is a very important coding tool in video coding. It decorrelates the pixel data and removes the redundancy among pixels so as to achieve compression. Traditionally, order-S transform is used in video and image coding. Latest video coding standards, such as H.264/AVC, adopt both order-4 and order-8 transforms. The adaptive use of more than one transforms of different sizes is known as Arbitrary Block-size Transform (ABT). Transforms other than order-4 and order-8 can also be used in ABT. It is expected larger transform size such as order-16 will benefit more in video sequences with higher resolutions such as nap and 1a8ap sequences. As a result, order-16 transform is introduced into ABT system., Fong, Chi Keung., Adviser: Wai Kuen Cham., Source: Dissertation Abstracts International, Volume: 73-04, Section: B, page: ., Thesis (Ph.D.)--Chinese University of Hong Kong, 2011., Includes bibliographical references., 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, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web., also in Chinese., isbn: 9781267099471, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Se presenta un sistema automático de captacion de datos de equipos remotos para diversas aplicaciones audiovisuales y multimedia, que da solución a las necesidades demandadas por el "Consell Comarcal de Menorca". Principalmente, la necesidad de un Web-Service que nutra a su pagina web www.menorca.es de fotografías y datos meteorologicos actuales. Hay que tener en cuenta que el cliente final es la administracion pública y uno de los requisitos que nos hara optar y decidir entre diferentes soluciones, es el plano economico. El sistema completo tiene que ser lo mas ajustado económicamente a las necesidades y que su mantenimiento no constituya un gasto importante. El sistema se divide en dos partes funcionales: Por un lado, la captacion de datos de los equipos remotos. Se requiere la captación de imagenes, con la posibilidad de diferentes resoluciones, y variedad de datos meteorologicos. Todo ello remotamente, a traves de tecnologia 3G y/o WiMAX. Por otro lado, la administracion y gestión de dichos datos para poderlos entregar al cliente cuando los demande. Para ello se implementa una aplicación, principalmente en PHP y MySQL con GUI (interfaz grafica de usuario), que es el eje neuronal del sistema. Un webservice denominado ADCAM. El webservice se ha pensado de forma escalable, para que mas clientes puedan utilizarlo. Además, es independiente al sistema que capta los datos, por lo tanto permite la interoperabilidad entre diferentes plataformas. En consecuencia, se pueden proveer diferentes servicios integrados dependiendo del techo económico u otras variables impuestas por un cliente. Se puede acceder desde internet y su tecnología basada en la web2.0 hace que cada usuario/cliente obtenga sus contenidos de forma simple, privada y rápida. Para finalizar, este proyecto plasma todo el proceso de implementación del sistema. Desde los requerimientos principales, hasta las mejoras del sistema final, obviando la implementación de la aplicacion ADCAM.

Tato práce se zabývá vlivem internetové sítě na médium fotografie a zejména pak tím, jak se působením sítě mění kvalitativní a kvantitativní hodnoty fotografického zobrazení. Zkoumání je směřováno především k nové zkušenosti způsobené mnohem rychlejším a hlavně početně rozsáhlejším přístupem k obrazovým sdělením. V první části diplomové práce je popisována historie přenosu obrazu a s ní spojený fenomén distribuce obrazu. Druhá část se dotýká problematiky digitální fotografie jakožto technologického postupu přinášejícího s sebou spoustu závažných otázek ohledně podstaty zobrazovacího média samotného. Hlavní, třetí část rozebírá problematiku obrazové databáze v prostředí internetu. Nejdříve je tu věnována pozornost kulturním souvislostem formy databáze a poté způsobům zpracování obrazů v databázích s ohledem na uživatelskou dostupnost a přístupnost., This thesis discursses the influence of internet on photographic medium and then especially with the way how the qualitative and quantitative values of photographic representation are being changed by the influence of web. Examination is aimed primarily at new experinence caused by much faster and mainly numericaly more extensive access to image information. In the first part of this work a history of image transmission is described together with the phenomenon of image distribution connected with it. Second part concerns the dilemma of digital photography as technological process which brings a lot of important questions regarding the essence of imaging medium itself. The third and main part deals with the problematics of image database in internet environment. Primarily, attention is paid to cultural consequences of database form and then to the methods of database image processing with regard to user availability and accessibility., Ústav reklamní fotografie a grafiky, obhájeno

In the first part, decoder based error concealment methods are discussed. An adaptive partition size (APS) temporal error concealment method is developed for H.264. We propose to use Weighted Double-Sided External Boundary Matching Error (WDS-EBME) to jointly measure the inter-MB boundary discontinuity, inter-partition boundary discontinuity and intra-partition block artifacts in the corrupted MB. By minimizing the WDS-EBME value of each partition, the best motion vectors of each candidate partition mode can be estimated, overall WDS-EBME of the MB concealed by each partition mode can then be evaluated and the best partition mode for the corrupted Macroblocks (MB) will be determined as the one with the smallest overall WDS-EBME. We also propose a progressive concealment order for the 4x4 partition mode., In this thesis, techniques for efficient error resilient video coding are investigated. Three parts of the work are discussed in this thesis., The last part of the thesis concerns the joint encoder-decoder error control method. A joint temporal error control method is proposed for H.264. It combines RDO-based macroblock (MB) classification at the encoder and adaptive partition size error concealment at the decoder. The encoder classifies the MBs by evaluating the sensitivity of the MBs as the RD cost between the concealment error and the bits needed for the additional motion information. Additional motion information such as the original motion vector or motion vector index can be transmitted for the error sensitive MBs. The decoder utilizes the additional motion information if any of these MBs get lost. Non-sensitive MBs and blocks are concealed by the APS method., The second part of this thesis investigates encoder based error control techniques. Firstly, a VLC/FLC data partitioning method is proposed for MPEG-4. It disables intra AC prediction and groups appropriate fixed length coded (FLC) syntaxes in a video packet (or slice) together to form a new partition. With intra AC prediction disabled, errors occurring in these FLC syntaxes will not cause spatial error propagation. It essentially classifies the syntaxes into two categories according to whether that syntax will cause spatial error propagation when an error occurs. Secondly, a redundant macroblock strategy is proposed for H.264. MB Differential Mean Square Error (DMSE) is employed to evaluate the error sensitivity of MBs. The most sensitive MBs are transmitted separately in additional slices while coarsely quantized copies of the MBs are placed in the original slice. When working with chessboard style Flexible Macroblock reordering (FMO) and fixed length slice mode (FMO-slicing), the scheme performs well against packet loss errors with acceptable overhead and it is highly compatible with original H.264 bitstream. Thirdly, a joint optimal bit allocation and rate control scheme is proposed for H.264 with redundant slice. The optimum ratio between each primary and redundant picture pair is analytically deduced. Rate function and distortion model for both representations are developed, and a simple close-form solution is provided to achieve joint optimum bit allocation., Video communication and other web-based video applications become popular in recent years. However, the transmission of the compressed video bit stream often suffers from imperfection of the communication channel, like path loss, multipath fading, co-channel interference, congestion, etc. Error resilient video coding techniques need to be employed to mitigate the channel errors, which include error concealment in the decoder, forward error correction in the encoder and joint encoder-decoder error control techniques., Li, Jie., Adviser: Ngan King Ngi., Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: ., Thesis (Ph.D.)--Chinese University of Hong Kong, 2009., Includes bibliographical references (leaves 137-146)., 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, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web., also in Chinese., isbn: 9781124960128, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

In the first part, some efficient algorithms are proposed to reduce the complexity of H.264 encoder, which is the latest state-of-the-art video coding standard. Intra and Inter mode decision play a vital role in H.264 encoder and can reduce the spatial and temporal redundancy significantly, but the computational cost is also high. Here, a fast Intra mode decision algorithm and a fast Inter mode decision algorithm are proposed. Experimental results show that the proposed algorithms not only save a lot of computational cost, but also maintain coding performance quite well. Moreover, a real time H.264 baseline codec is implemented on mobile device. Based on our real time H.264 codec, an H.264 based mobile video conferencing system is achieved., The objective of this thesis is to develop some efficient and perceptual image and video coding techniques. Two parts of the work are investigated in this thesis., The second part of this thesis investigates two kinds of perceptual picture coding techniques. One is the just noticeable distortion (JND) based picture coding. Firstly, a DCT based spatio-temporal JND model is proposed, which is an efficient model to represent the perceptual redundancies existing in images and is consistent with the human visual system (HVS) characteristic. Secondly, the proposed JND model is incorporated into image and video coding to improve the perceptual quality. Based on the JND model, a transparent image coder and a perceptually optimized H.264 video coder are implemented. Another technique is the image compression scheme based on the recent advances in texture synthesis. In this part, an image compression scheme is proposed with the perceptual visual quality as the performance criterion instead of the pixel-wise fidelity. As demonstrated in extensive experiments, the proposed techniques can improve the perceptual quality of picture coding significantly., Wei Zhenyu., Adviser: Ngan Ngi., Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: ., Thesis (Ph.D.)--Chinese University of Hong Kong, 2009., Includes bibliographical references (leaves 148-154)., 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, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web., also in Chinese., isbn: 9781124960142, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

In the first part, some efficient algorithms are proposed to reduce the complexity of H.264 encoder, which is the latest state-of-the-art video coding standard. Intra and Inter mode decision play a vital role in H.264 encoder and can reduce the spatial and temporal redundancy significantly, but the computational cost is also high. Here, a fast Intra mode decision algorithm and a fast Inter mode decision algorithm are proposed. Experimental results show that the proposed algorithms not only save a lot of computational cost, but also maintain coding performance quite well. Moreover, a real time H.264 baseline codec is implemented on mobile device. Based on our real time H.264 codec, an H.264 based mobile video conferencing system is achieved., The objective of this thesis is to develop some efficient and perceptual image and video coding techniques. Two parts of the work are investigated in this thesis., The second part of this thesis investigates two kinds of perceptual picture coding techniques. One is the just noticeable distortion (JND) based picture coding. Firstly, a DCT based spatio-temporal JND model is proposed, which is an efficient model to represent the perceptual redundancies existing in images and is consistent with the human visual system (HVS) characteristic. Secondly, the proposed JND model is incorporated into image and video coding to improve the perceptual quality. Based on the JND model, a transparent image coder and a perceptually optimized H.264 video coder are implemented. Another technique is the image compression scheme based on the recent advances in texture synthesis. In this part, an image compression scheme is proposed with the perceptual visual quality as the performance criterion instead of the pixel-wise fidelity. As demonstrated in extensive experiments, the proposed techniques can improve the perceptual quality of picture coding significantly., Wei Zhenyu., Adviser: Ngan Ngi., Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: ., Thesis (Ph.D.)--Chinese University of Hong Kong, 2009., Includes bibliographical references (leaves 148-154)., 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, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web., also in Chinese., isbn: 9781124960142, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

The scattering properties of the medium ultimately determine the outcome of the image transmission. For ocean optics research the scattering properties are often conveniently described and measured in general by the scattering coefficient (b), which determines the possibility of a photon to be scattered away from its original traveling direction per unit length by the medium molecules, constituents within (i.e. particles) and turbulence. As we know, this parameter (b) is an integration of the volume scattering or phase function, Beta, which details such probability by the relative directions of incoming and out-going photons. These inherent optical properties (IOP), although measured frequently due to their important applications in ocean optics, especially in remote sensing, cannot be applied to underwater imaging issues directly, since they inherently reflect the chance of the single scattering., Presented at the International Conference on Current Problems in Optics of Natural Waters (4th) held in Nizhny Novgorod, Russia on 11-15 Sep 2007. Published in the Proceedings of the International Conference on Current Problems in Optics of Natural Waters (4th), p86-90, 2007.

In this paper, we examine the spatial diversity of cooperative communications for image transmission without deploying multiple antennas at the transmitter. We propose a novel region of interest (ROI)-based scheme for image transmission over wireless cooperative/relay fading channels. By having the relay terminal assist the direct communications, we can increase the resilience for ROI against the error-prone fading channels. Our proposed scheme significantly improves the performance of ROI compared to the direct communications (no-cooperation) and conventional relay networks without performing any forward error correction. Although we focus on the adaptive decode-forward (ADF) relay protocol, our proposed scheme can be easily adopted to any other relaying protocol such as fixed decode-forward (FDF), amplify-forward (AF), hybrid decode-amplify-forward (HDAF), and distributed-Alamouti space--time coding. Simulation results show that under the the same total transmit power constraint our proposed scheme significant outperforms the conventional ones in terms of bit error rate (BER) and peak signal-to-noise ratio (PSNR).

A robust image transmission scheme deploying distributed-Alamouti space-time code (STC) over wireless relay networks is proposed. Specifically, we propose a cross-layer design combining application, networking, and physical layer to enhance the quality of multimedia data over error-prone wireless channels. At the application layer, a coded image sequence based on the wavelet transform is divided into two priorities. The higher priority contains the most significant information of image and the lower priority conveys less important information. At the physical layer, two pre-assigned relays cooperate to form a distributed-Alamouti code which help the source to transmit the low priority sequence of the image over error-prone wireless channels. At the networking layer, among the whole relay nodes in the networks we select two relay nodes which provides the maximum signal-to-noise ratio to convey the higher priority. With this strategy, we implicitly achieve unequal error protection for image transmission without controlling power or varying modulation and coding at the transmitter at the expense of increasing network's overhead (i.e. feedback information). The selection of relays needs limited feedback, hence, enabling our proposed scheme feasible in practical applications. Analytical and simulation results are provided to verify our proposal. It has been shown that the image quality is remarkably enhanced in terms of objective quality using the proposed scheme compared to the conventional transmission schemes.

Thesis (Elec.E)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981., MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING., Bibliography: leaves 147-148., by Raleigh Cedric Gallington., Elec.E

Thesis (Elec.E)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981., MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING., Bibliography: leaves 147-148., by Raleigh Cedric Gallington., Elec.E

Thesis (Elec.E)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981., MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING., Bibliography: leaves 147-148., by Raleigh Cedric Gallington., Elec.E

Thesis (Elec.E)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1981., MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING., Bibliography: leaves 147-148., by Raleigh Cedric Gallington., Elec.E

Multimedia application has become extremely popular nowadays. Digital video products such as DVD player, DVD recorder, Digital TV system and Personal Video Recorder are entering everyone's home and bringing an exciting multimedia environment to the consumers. The improvement in the video quality is a key factor in the success of multimedia industry, which is facilitated by the advancement in multimedia, VLSI and networking technology. With the improvement in VLSI technology, more advanced and computationally complex video processing algorithms can be realized into consumer products and hence, producing high quality multimedia applications. Postprocessing is the technique to enhance the video quality for display. In this thesis, two topics in postprocessing are investigated: error concealment and video format conversion. Nowadays, many multimedia applications are integrated into some existing networks, for examples, video conferencing on the Internet, VOD with your 3G mobile phone, etc... However, those networks are unreliable and packets may be lost or corrupted during the transmission. The loss of information caused by the transmission errors can produce an adverse degradation in visual quality. Error concealment is a technique to recover the lost information and improve the quality of the corrupted video. In this thesis, we provide two algorithms to address the issue: "Temporal error concealment for video transmission with edge reconstruction" and "A Partitioned Linear Minimum Mean Square Estimator for Error Concealment". In the first algorithm, the edge information is considered in the estimation of the missing motion vector to improve the prediction accuracy. In the second algorithm, the multi-hypothesis motion compensated technique is employed to reduce the prediction error. The second problem in multimedia application is the different display formats in use. For example, the TV transmission system (PAL, NTSC, SECAM) adopts interlaced video while the PC communi

Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982., MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING, Bibliography: leaves 166-174., by Yao-Ming Chao., Sc.D.

Multimedia application has become extremely popular nowadays. Digital video products such as DVD player, DVD recorder, Digital TV system and Personal Video Recorder are entering everyone's home and bringing an exciting multimedia environment to the consumers. The improvement in the video quality is a key factor in the success of multimedia industry, which is facilitated by the advancement in multimedia, VLSI and networking technology. With the improvement in VLSI technology, more advanced and computationally complex video processing algorithms can be realized into consumer products and hence, producing high quality multimedia applications. Postprocessing is the technique to enhance the video quality for display. In this thesis, two topics in postprocessing are investigated: error concealment and video format conversion. Nowadays, many multimedia applications are integrated into some existing networks, for examples, video conferencing on the Internet, VOD with your 3G mobile phone, etc... However, those networks are unreliable and packets may be lost or corrupted during the transmission. The loss of information caused by the transmission errors can produce an adverse degradation in visual quality. Error concealment is a technique to recover the lost information and improve the quality of the corrupted video. In this thesis, we provide two algorithms to address the issue: "Temporal error concealment for video transmission with edge reconstruction" and "A Partitioned Linear Minimum Mean Square Estimator for Error Concealment". In the first algorithm, the edge information is considered in the estimation of the missing motion vector to improve the prediction accuracy. In the second algorithm, the multi-hypothesis motion compensated technique is employed to reduce the prediction error. The second problem in multimedia application is the different display formats in use. For example, the TV transmission system (PAL, NTSC, SECAM) adopts interlaced video while the PC communi

Multimedia application has become extremely popular nowadays. Digital video products such as DVD player, DVD recorder, Digital TV system and Personal Video Recorder are entering everyone's home and bringing an exciting multimedia environment to the consumers. The improvement in the video quality is a key factor in the success of multimedia industry, which is facilitated by the advancement in multimedia, VLSI and networking technology. With the improvement in VLSI technology, more advanced and computationally complex video processing algorithms can be realized into consumer products and hence, producing high quality multimedia applications. Postprocessing is the technique to enhance the video quality for display. In this thesis, two topics in postprocessing are investigated: error concealment and video format conversion. Nowadays, many multimedia applications are integrated into some existing networks, for examples, video conferencing on the Internet, VOD with your 3G mobile phone, etc... However, those networks are unreliable and packets may be lost or corrupted during the transmission. The loss of information caused by the transmission errors can produce an adverse degradation in visual quality. Error concealment is a technique to recover the lost information and improve the quality of the corrupted video. In this thesis, we provide two algorithms to address the issue: "Temporal error concealment for video transmission with edge reconstruction" and "A Partitioned Linear Minimum Mean Square Estimator for Error Concealment". In the first algorithm, the edge information is considered in the estimation of the missing motion vector to improve the prediction accuracy. In the second algorithm, the multi-hypothesis motion compensated technique is employed to reduce the prediction error. The second problem in multimedia application is the different display formats in use. For example, the TV transmission system (PAL, NTSC, SECAM) adopts interlaced video while the PC communi

This pilot program is funded by the Army Medical Department (AMEDD) to demonstrate a real-time detection and rapid response system for local area defense using the University of Maryland Baltimore (UMB) Campus as a testbed. Additional goals includes the identification of Rapid Response teams performance and the coordination of the Campus and Baltimore City Emergency Management Plans and Responses in the event of a environmental sensor trigger. Transmission of images from UMB campus video surveillance cameras and from a mobile wireless platform to North Atlantic Treaty Organization (NATO) Headquarters and University of Regensberg Germany was also achieved. Emergency Operation Center Remote expert review and evaluation of telecommunications were carried out. This demonstration can serve as a model system to test performance of integrated environmental sensors to support Homeland Security threat detection, for protection of a terrorist target that crossed local, City, State and Federal jurisdiction in an urban testbed setting of a major U.S, city., The original document contains color images.

Bo Yan., "May 2004.", Thesis (Ph.D.)--Chinese University of Hong Kong, 2004., Includes bibliographical references (p. 117-131)., 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., s in English and Chinese., http://library.cuhk.edu.hk/record=b6073624, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Bo Yan., "May 2004.", Thesis (Ph.D.)--Chinese University of Hong Kong, 2004., Includes bibliographical references (p. 117-131)., 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., s in English and Chinese., http://library.cuhk.edu.hk/record=b6073624, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Nowadays, the Internet connects hospitals, medical institutions and people together. In this thesis, we focus on a medical application on ultrasound image processing and transmission. We consider that a pregnant woman takes her ultrasound examination in a local hospital, and the diagnosis and analysis of her ultrasound video (or image sequences) could be done remotely via the Internet. It is also possible for medical professionals and her family members from a distance to simultaneously view her ultrasound video using a multicast-capable network. In order to facilitate clinicians' diagnosis and improve medical information distribution, we address the issues in the clinical system related to the following two components. The first component focuses on automatic detection of fetal head features in ultrasound images. In clinics, fetal biometric measurement is done manually in the qualified ultrasound scanning images, in which some important predefined features exist. We present simple and new methods for automatic detection of these features in a single head ultrasound image. We also describe our system and criteria for ranking multiple images to facilitate clinicians' subsequent image selection and measurements in a sequence of ultrasound images. The results show that the methods can successfully identify features, and our system's ranking and the clinicians' ranking are well matched (with the hit ratio of 72.5%). The second component in the system is to offer quality real-time medical video to users over multicast networks. Since the video packet loss is inevitable, they have to be mostly recovered at clients. We propose and study an effective feedback-free recovery scheme for layered video in which the server multicasts FEC packets and replicated delayed (ReD) version of the streams in parallel with the video layers and the receivers, depending on their local losses, autonomously and dynamically join these layers to minimize their residual error rates (i.e., error a

Nowadays, the Internet connects hospitals, medical institutions and people together. In this thesis, we focus on a medical application on ultrasound image processing and transmission. We consider that a pregnant woman takes her ultrasound examination in a local hospital, and the diagnosis and analysis of her ultrasound video (or image sequences) could be done remotely via the Internet. It is also possible for medical professionals and her family members from a distance to simultaneously view her ultrasound video using a multicast-capable network. In order to facilitate clinicians' diagnosis and improve medical information distribution, we address the issues in the clinical system related to the following two components. The first component focuses on automatic detection of fetal head features in ultrasound images. In clinics, fetal biometric measurement is done manually in the qualified ultrasound scanning images, in which some important predefined features exist. We present simple and new methods for automatic detection of these features in a single head ultrasound image. We also describe our system and criteria for ranking multiple images to facilitate clinicians' subsequent image selection and measurements in a sequence of ultrasound images. The results show that the methods can successfully identify features, and our system's ranking and the clinicians' ranking are well matched (with the hit ratio of 72.5%). The second component in the system is to offer quality real-time medical video to users over multicast networks. Since the video packet loss is inevitable, they have to be mostly recovered at clients. We propose and study an effective feedback-free recovery scheme for layered video in which the server multicasts FEC packets and replicated delayed (ReD) version of the streams in parallel with the video layers and the receivers, depending on their local losses, autonomously and dynamically join these layers to minimize their residual error rates (i.e., error a

Pun-Mo Ho., Thesis (M.Phil.)--Chinese University of Hong Kong, 2003., Includes bibliographical references (leaves 90-95)., s in English and Chinese., Chapter 1 --- Introduction --- p.1, Chapter 1.1 --- Background --- p.1, Chapter 1.2 --- Existing Approaches --- p.2, Chapter 1.3 --- Our Approach --- p.3, Chapter 1.4 --- Structure of the Thesis --- p.4, Chapter 2 --- Related Work --- p.5, Chapter 2.1 --- Compression for Navigation --- p.5, Chapter 2.1.1 --- Light Field/Lumigraph --- p.5, Chapter 2.1.2 --- Surface Light Field --- p.6, Chapter 2.1.3 --- Concentric Mosaics --- p.6, Chapter 2.1.4 --- On the Compression --- p.7, Chapter 2.2 --- Compression for Relighting --- p.7, Chapter 2.2.1 --- Previous Approaches --- p.7, Chapter 2.2.2 --- Our Approach --- p.8, Chapter 3 --- Image-Based Relighting --- p.9, Chapter 3.1 --- Plenoptic Illumination Function --- p.9, Chapter 3.2 --- Sampling and Relighting --- p.11, Chapter 3.3 --- Overview --- p.13, Chapter 3.3.1 --- Codec Overview --- p.13, Chapter 3.3.2 --- Image Acquisition --- p.15, Chapter 3.3.3 --- Experiment Data Sets --- p.16, Chapter 4 --- Data Preparation --- p.18, Chapter 4.1 --- Block Division --- p.18, Chapter 4.2 --- Color Model --- p.23, Chapter 4.3 --- Mean Extraction --- p.24, Chapter 5 --- Principal Component Analysis --- p.29, Chapter 5.1 --- Overview --- p.29, Chapter 5.2 --- Singular Value Decomposition --- p.30, Chapter 5.3 --- Dimensionality Reduction --- p.34, Chapter 5.4 --- Evaluation --- p.37, Chapter 6 --- Eigenimage Coding --- p.39, Chapter 6.1 --- Transform Coding --- p.39, Chapter 6.1.1 --- Discrete Cosine Transform --- p.40, Chapter 6.1.2 --- Discrete Wavelet Transform --- p.47, Chapter 6.2 --- Evaluation --- p.49, Chapter 6.2.1 --- Statistical Evaluation --- p.49, Chapter 6.2.2 --- Visual Evaluation --- p.52, Chapter 7 --- Relighting Coefficient Coding --- p.57, Chapter 7.1 --- Quantization and Bit Allocation --- p.57, Chapter 7.2 --- Evaluation --- p.62, Chapter 7.2.1 --- Statistical Evaluation --- p.62, Chapter 7.2.2 --- Visual Evaluation --- p.62, Chapter 8 --- Relighting --- p.65, Chapter 8.1 --- Overview --- p.66, Chapter 8.2 --- First-Phase Decoding --- p.66, Chapter 8.3 --- Second-Phase Decoding --- p.68, Chapter 8.3.1 --- Software Relighting --- p.68, Chapter 8.3.2 --- Hardware-Assisted Relighting --- p.71, Chapter 9 --- Overall Evaluation --- p.81, Chapter 9.1 --- Compression of IAIs --- p.81, Chapter 9.1.1 --- Statistical Evaluation --- p.81, Chapter 9.1.2 --- Visual Evaluation --- p.86, Chapter 9.2 --- Hardware-Assisted Relighting --- p.86, Chapter 10 --- Conclusion --- p.89, Bibliography --- p.90, http://library.cuhk.edu.hk/record=b5891490, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Pun-Mo Ho., Thesis (M.Phil.)--Chinese University of Hong Kong, 2003., Includes bibliographical references (leaves 90-95)., s in English and Chinese., Chapter 1 --- Introduction --- p.1, Chapter 1.1 --- Background --- p.1, Chapter 1.2 --- Existing Approaches --- p.2, Chapter 1.3 --- Our Approach --- p.3, Chapter 1.4 --- Structure of the Thesis --- p.4, Chapter 2 --- Related Work --- p.5, Chapter 2.1 --- Compression for Navigation --- p.5, Chapter 2.1.1 --- Light Field/Lumigraph --- p.5, Chapter 2.1.2 --- Surface Light Field --- p.6, Chapter 2.1.3 --- Concentric Mosaics --- p.6, Chapter 2.1.4 --- On the Compression --- p.7, Chapter 2.2 --- Compression for Relighting --- p.7, Chapter 2.2.1 --- Previous Approaches --- p.7, Chapter 2.2.2 --- Our Approach --- p.8, Chapter 3 --- Image-Based Relighting --- p.9, Chapter 3.1 --- Plenoptic Illumination Function --- p.9, Chapter 3.2 --- Sampling and Relighting --- p.11, Chapter 3.3 --- Overview --- p.13, Chapter 3.3.1 --- Codec Overview --- p.13, Chapter 3.3.2 --- Image Acquisition --- p.15, Chapter 3.3.3 --- Experiment Data Sets --- p.16, Chapter 4 --- Data Preparation --- p.18, Chapter 4.1 --- Block Division --- p.18, Chapter 4.2 --- Color Model --- p.23, Chapter 4.3 --- Mean Extraction --- p.24, Chapter 5 --- Principal Component Analysis --- p.29, Chapter 5.1 --- Overview --- p.29, Chapter 5.2 --- Singular Value Decomposition --- p.30, Chapter 5.3 --- Dimensionality Reduction --- p.34, Chapter 5.4 --- Evaluation --- p.37, Chapter 6 --- Eigenimage Coding --- p.39, Chapter 6.1 --- Transform Coding --- p.39, Chapter 6.1.1 --- Discrete Cosine Transform --- p.40, Chapter 6.1.2 --- Discrete Wavelet Transform --- p.47, Chapter 6.2 --- Evaluation --- p.49, Chapter 6.2.1 --- Statistical Evaluation --- p.49, Chapter 6.2.2 --- Visual Evaluation --- p.52, Chapter 7 --- Relighting Coefficient Coding --- p.57, Chapter 7.1 --- Quantization and Bit Allocation --- p.57, Chapter 7.2 --- Evaluation --- p.62, Chapter 7.2.1 --- Statistical Evaluation --- p.62, Chapter 7.2.2 --- Visual Evaluation --- p.62, Chapter 8 --- Relighting --- p.65, Chapter 8.1 --- Overview --- p.66, Chapter 8.2 --- First-Phase Decoding --- p.66, Chapter 8.3 --- Second-Phase Decoding --- p.68, Chapter 8.3.1 --- Software Relighting --- p.68, Chapter 8.3.2 --- Hardware-Assisted Relighting --- p.71, Chapter 9 --- Overall Evaluation --- p.81, Chapter 9.1 --- Compression of IAIs --- p.81, Chapter 9.1.1 --- Statistical Evaluation --- p.81, Chapter 9.1.2 --- Visual Evaluation --- p.86, Chapter 9.2 --- Hardware-Assisted Relighting --- p.86, Chapter 10 --- Conclusion --- p.89, Bibliography --- p.90, http://library.cuhk.edu.hk/record=b5891490, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Nowadays, the Internet connects hospitals, medical institutions and people together. In this thesis, we focus on a medical application on ultrasound image processing and transmission. We consider that a pregnant woman takes her ultrasound examination in a local hospital, and the diagnosis and analysis of her ultrasound video (or image sequences) could be done remotely via the Internet. It is also possible for medical professionals and her family members from a distance to simultaneously view her ultrasound video using a multicast-capable network. In order to facilitate clinicians' diagnosis and improve medical information distribution, we address the issues in the clinical system related to the following two components. The first component focuses on automatic detection of fetal head features in ultrasound images. In clinics, fetal biometric measurement is done manually in the qualified ultrasound scanning images, in which some important predefined features exist. We present simple and new methods for automatic detection of these features in a single head ultrasound image. We also describe our system and criteria for ranking multiple images to facilitate clinicians' subsequent image selection and measurements in a sequence of ultrasound images. The results show that the methods can successfully identify features, and our system's ranking and the clinicians' ranking are well matched (with the hit ratio of 72.5%). The second component in the system is to offer quality real-time medical video to users over multicast networks. Since the video packet loss is inevitable, they have to be mostly recovered at clients. We propose and study an effective feedback-free recovery scheme for layered video in which the server multicasts FEC packets and replicated delayed (ReD) version of the streams in parallel with the video layers and the receivers, depending on their local losses, autonomously and dynamically join these layers to minimize their residual error rates (i.e., error a

Ngai Li., Thesis (Ph.D.)--Chinese University of Hong Kong, 2001., Includes bibliographical references (p. 75-[78])., 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., s in English and Chinese., http://library.cuhk.edu.hk/record=b6073340, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)