An improvement to MBASIC algorithm for 3D motion and depth estimation

Cataloged from PDF version of article.In model-based coding of facial images, the accuracy of motion and depth parameter estimates strongly affects the coding efficiency. MBASIC is a simple and effective iterative algorithm (recently proposed by Aizawa et al.) for 3-D motion and depth estimation when the initial depth estimates are relatively accurate. In this correspondence, we analyze its performance in the presence of errors in the initial depth estimates and propose a modification to MBASIC algorithm that significantly improves its robustness to random errors with only a small increase in the computational load

Three-dimensional facial motion and structure estimation in video coding

Ankara : Department of Electrical and Electronics Engineering and the Institute of Engineering and Science of Bilkent Univ., 1994.Thesis (Ph.D.) -- Bilkent University, 1994.Includes bibliographical references leaves 81-89.We propose a novel formulation where 3-D global and local motion estimation and the adaptation of a generic wire-frame model to a particular speaker are considered simultaneously within an optical flow based framework including the photometric effects of the motion. We use a flexible wire-frame model whose local structure is characterized by the normal vectors of the patches which are related to the coordinates of the nodes. Geometric constraints that describe the propagation of the movement of the nodes are introduced, which are then efficiently utilized to reduce the number of independent structure parameters. A stochastic relaxation algorithm has been used to determine optimum global motion estimates and the parameters describing the structure of the wire-frame model. For the initialization of the motion and structure parameters, a modified feature based algorithm is used whose performance has also been compared with the existing methods. Results with both simulated and real facial image sequences are provided.Bozdağı, GözdePh.D

3-D Motion Estimation and Wireframe Adaptation Including Photometric Effects for Model-Based Coding of Facial Image Sequences

Cataloged from PDF version of article.We propose a novel formulation where 3-D global and local motion estimation and the adaptation of a generic wireframe model to a particular speaker are considered simultaneously within an optical flow based framework including the photometric effects of the motion. We use a flexible wireframe model whose local structure is characterized by the normal vectors of the patches which are related to the coordinates of the nodes. Geometrical constraints that describe the propagation of the movement of the nodes are introduced, which are then efficiently utilized to reduce the number of independent structure parameters. A stochastic relaxation algorithm has been used to determine optimum global motion estimates and the parameters describing the structure of the wireframe model. Results with both simulated and real facial image sequences are provided

Publications of the Jet Propulsion Laboratory 1976

The formalized technical reporting, released January through December 1975, that resulted from scientific and engineering work performed, or managed, by the Jet Propulsion Laboratory is described and indexed. The following classes of publications are included: (1) technical reports; (2) technical memorandums; (3) articles from bi-monthly Deep Space Network (DSN) progress report; (4) special publications; and (5) articles published in the open literature. The publications are indexed by: (1) author, (2) subject, and (3) publication type and number. A descriptive entry appears under the name of each author of each publication; an abstract is included with the entry for the primary (first-listed) author. Unless designated otherwise, all publications listed are unclassified

Model-based computer vision: motion analysis, motion-based segmentation, 3D object recognition.

by Man-lee Liu.Thesis (M.Phil.)--Chinese University of Hong Kong, 1998.Includes bibliographical references (leaves 143-151).LIST OF TABLES --- p.viLIST OF FIGURES --- p.xiiCHAPTERChapter 1 --- Introduction --- p.1Chapter 1.1 --- Model-based Motion Analysis --- p.2Chapter 1.1.1 --- With 3D-to-3D Point Correspondences --- p.4Chapter 1.1.2 --- With 2D-to-3D Point Correspondences --- p.5Chapter 1.1.3 --- With 2D-to-2D Point Correspondences --- p.6Chapter 1.2 --- Motion-based Segmentation --- p.7Chapter 1.3 --- 3D Object Recognition --- p.8Chapter 1.4 --- Organization of the Thesis --- p.8Chapter 2 --- Literature Review and Summary of Contributions --- p.10Chapter 2.1 --- Model-based Motion Analysis --- p.10Chapter 2.1.1 --- With 3D-to-3D Point Correspondences --- p.10Chapter 2.1.2 --- With 2D-to-3D Point Correspondences --- p.13Chapter 2.1.2.1 --- An Iterative Approach: Lowe's Algorithm --- p.18Chapter 2.1.2.2 --- A Linear Approach: Faugeras's Algorithm --- p.19Chapter 2.1.3 --- With 2D-to-2D Point Correspondences --- p.22Chapter 2.2 --- Motion-based Segmentation --- p.27Chapter 2.3 --- 3D Object Recognition --- p.28Chapter 2.4 --- Summary of Contributions --- p.30Chapter 3 --- Model-based Motion Analysis with 2D-to-3D Point Correspondences --- p.34Chapter 3.1 --- A new Iterative Algorithm for the Perspective-4-point Problem: TL-algorithm --- p.34Chapter 3.1.1 --- Algorithm --- p.35Chapter 3.1.2 --- Experiment --- p.37Chapter 3.1.2.1 --- Experiment using Synthetic Data --- p.38Chapter 3.1.2.2 --- Experiment using Real Data --- p.42Chapter 3.2 --- An Enhancement of Faugeras's Algorithm --- p.42Chapter 3.2.1 --- Experimental Comparison between the Original Faugeras's Algorithm and the Modified One --- p.44Chapter 3.2.1.1 --- Experiment One: Fixed Motion --- p.44Chapter 3.2.1.2 --- Experiment Two: Using Motion Generated Ran- domly --- p.50Chapter 3.2.2 --- Discussion --- p.54Chapter 3.3 --- A new Linear Algorithm for the Model-based Motion Analysis: Six-point Algorithm --- p.55Chapter 3.3.1 --- General Information of the Six-point Algorithm --- p.55Chapter 3.3.2 --- Original Version of the Six-point Algorithm --- p.56Chapter 3.3.2.1 --- Linear Solution Part --- p.56Chapter 3.3.2.2 --- Constraint Satisfaction --- p.58Use of Representation of Rotations by Quaternion --- p.62Use of Singular Value Decomposition --- p.62Determination of the translational matrix --- p.63Chapter 3.3.3 --- Second Version of the Six-point Algorithm --- p.64Chapter 3.3.4 --- Experiment --- p.65Chapter 3.3.4.1 --- With Synthetic Data --- p.66Experiment One: With Fixed Motion --- p.66Experiment Two: With Motion Generated Randomly --- p.77Chapter 3.3.4.2 --- With Real Data --- p.93Chapter 3.3.5 --- Summary of the Six-Point Algorithm --- p.93Chapter 3.3.6 --- A Visual Tracking System by using Six-point Algorithm --- p.95Chapter 3.4 --- Comparison between TL-algorithm and Six-point Algorithm developed --- p.97Chapter 3.5 --- Summary --- p.102Chapter 4 --- Motion-based Segmentation --- p.104Chapter 4.1 --- A new Approach with 3D-to-3D Point Correspondences --- p.104Chapter 4.1.1 --- Algorithm --- p.105Chapter 4.1.2 --- Experiment --- p.109Chapter 4.2 --- A new Approach with 2D-to-3D Point Correspondences --- p.112Chapter 4.2.1 --- Algorithm --- p.112Chapter 4.2.2 --- Experiment --- p.116Chapter 4.2.2.1 --- Experiment using synthetic data --- p.116Chapter 4.2.2.2 --- Experiment using real image sequence --- p.119Chapter 4.3 --- Summary --- p.119Chapter 5 --- 3D Object Recognition --- p.121Chapter 5.1 --- Proposed Algorithm for the 3D Object Recognition --- p.122Chapter 5.1.1 --- Hypothesis step --- p.122Chapter 5.1.2 --- Verification step --- p.124Chapter 5.2 --- 3D Object Recognition System --- p.125Chapter 5.2.1 --- System in Matlab: --- p.126Chapter 5.2.2 --- System in Visual C++ --- p.129Chapter 5.3 --- Experiment --- p.131Chapter 5.3.1 --- System in Matlab --- p.132Chapter 5.3.2 --- System in Visual C++ --- p.136Chapter 5.4 --- Summary --- p.139Chapter 6 --- Conclusions --- p.140REFERENCES --- p.142APPENDIXChapter A --- Representation of Rotations by Quaternion --- p.152Chapter B --- Constrained Optimization --- p.15

Automated 3D object modeling from aerial video imagery

Research in physically accurate 3D modeling of a scene is gaining momentum because of its far reaching applications in civilian and defense sectors. The modeled 3D scene must conform both geometrically and spectrally to the real world for all the applications. Geometric modeling of a scene can be achieved in many ways of which the two most popular methods are - a) using multiple 2D passive images of the scene also called as stereo vision and b) using 3D point clouds like Lidar (Light detection and ranging) data. In this research work, we derive the 3D models of objects in a scene using passive aerial video imagery. At present, this geometric modeling requires a lot of manual intervention due to a variety of factors like sensor noise, low contrast conditions during image capture, etc. Hence long time periods, in the order of weeks and months, are required to model even a small scene. This thesis focuses on automating the process of geometric modeling of objects in a scene from passive aerial video imagery. The aerial video frames are stitched into stereo mosaics. These stereo mosaics not only provide the elevation information of a scene but also act as good 3D visualization tools. The 3D information obtained from the stereo mosaics is used to identify the various 3D objects, especially man-made buildings using probabilistic inference provided by Bayesian Networks. The initial 3D building models are further optimized by projecting them on to the individual video frames. The limitations of the state-of-art technology in attaining these goals are presented along with the techniques to overcome them. The improvement that can be achieved in the accuracy of the 3D models when Lidar data is fused with aerial video during the object identification process is also examined

The deep space network

Summaries are given of Deep Space Network progress in flight project support, tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations

Publications of the Jet Propulsion Laboratory, January through December 1974

Formalized technical reporting is described and indexed, which resulted from scientific and engineering work performed, or managed, by the Jet Propulsion Laboratory. The five classes of publications included are technical reports, technical memorandums, articles from the bimonthly Deep Space Network Progress Report, special publications, and articles published in the open literature. The publications are indexed by author, subject, and publication type and number

Optimizing IETF multimedia signaling protocols and architectures in 3GPP networks : an evolutionary approach

Signaling in Next Generation IP-based networks heavily relies in the family of multimedia signaling protocols defined by IETF. Two of these signaling protocols are RTSP and SIP, which are text-based, client-server, request-response signaling protocols aimed at enabling multimedia sessions over IP networks. RTSP was conceived to set up streaming sessions from a Content / Streaming Server to a Streaming Client, while SIP was conceived to set up media (e.g.: voice, video, chat, file sharing, …) sessions among users. However, their scope has evolved and expanded over time to cover virtually any type of content and media session. As mobile networks progressively evolved towards an IP-only (All-IP) concept, particularly in 4G and 5G networks, 3GPP had to select IP-based signaling protocols for core mobile services, as opposed to traditional SS7-based protocols used in the circuit-switched domain in use in 2G and 3G networks. In that context, rather than reinventing the wheel, 3GPP decided to leverage Internet protocols and the work carried on by the IETF. Hence, it was not surprise that when 3GPP defined the so-called Packet-switched Streaming Service (PSS) for real-time continuous media delivery, it selected RTSP as its signaling protocol and, more importantly, SIP was eventually selected as the core signaling protocol for all multimedia core services in the mobile (All-)IP domain. This 3GPP decision to use off-the-shelf IETF-standardized signaling protocols has been a key cornerstone for the future of All-IP fixed / mobile networks convergence and Next Generation Networks (NGN) in general. In this context, the main goal of our work has been analyzing how such general purpose IP multimedia signaling protocols are deployed and behave over 3GPP mobile networks. Effectively, usage of IP protocols is key to enable cross-vendor interoperability. On the other hand, due to the specific nature of the mobile domain, there are scenarios where it might be possible to leverage some additional “context” to enhance the performance of such protocols in the particular case of mobile networks. With this idea in mind, the bulk of this thesis work has consisted on analyzing and optimizing the performance of SIP and RTSP multimedia signaling protocols and defining optimized deployment architectures, with particular focus on the 3GPP PSS and the 3GPP Mission Critical Push-to-Talk (MCPTT) service. This work was preceded by a detailed analysis work of the performance of underlying IP, UDP and TCP protocol performance over 3GPP networks, which provided the best baseline for the future work around IP multimedia signaling protocols. Our contributions include the proposal of new optimizations to enhance multimedia streaming session setup procedures, detailed analysis and optimizations of a SIP-based Presence service and, finally, the definition of new use cases and optimized deployment architectures for the 3GPP MCPTT service. All this work has been published in the form of one book, three papers published in JCR cited International Journals, 5 articles published in International Conferences, one paper published in a National Conference and one awarded patent. This thesis work provides a detailed description of all contributions plus a comprehensive overview of their context, the guiding principles beneath all contributions, their applicability to different network deployment technologies (from 2.5G to 5G), a detailed overview of the related OMA and 3GPP architectures, services and design principles. Last but not least, the potential evolution of this research work into the 5G domain is also outlined as well.Els mecanismes de Senyalització en xarxes de nova generació es fonamenten en protocols de senyalització definits per IETF. En particular, SIP i RTSP són dos protocols extensibles basats en missatges de text i paradigma petició-resposta. RTSP va ser concebut per a establir sessions de streaming de continguts, mentre SIP va ser creat inicialment per a facilitar l’establiment de sessions multimèdia (veu, vídeo, xat, compartició) entre usuaris. Tot i així, el seu àmbit d’aplicació s’ha anat expandint i evolucionant fins a cobrir virtualment qualsevol tipus de contingut i sessió multimèdia. A mesura que les xarxes mòbils han anat evolucionant cap a un paradigma “All-IP”, particularment en xarxes 4G i 5G, 3GPP va seleccionar els protocols i arquitectures destinats a gestionar la senyalització dels serveis mòbils presents i futurs. En un moment determinat 3GPP decideix que, a diferència dels sistemes 2G i 3G que fan servir protocols basats en SS7, els sistemes de nova generació farien servir protocols estandarditzats per IETF. Quan 3GPP va començar a estandarditzar el servei de Streaming sobre xarxes mòbils PSS (Packet-switched Streaming Service) va escollir el protocol RTSP com a mecanisme de senyalització. Encara més significatiu, el protocol SIP va ser escollit com a mecanisme de senyalització per a IMS (IP Multimedia Subsystem), l’arquitectura de nova generació que substituirà la xarxa telefònica tradicional i permetrà el desplegament de nous serveis multimèdia. La decisió per part de 3GPP de seleccionar protocols estàndards definits per IETF ha representat una fita cabdal per a la convergència del sistemes All-IP fixes i mòbils, i per al desenvolupament de xarxes NGN (Next Generation Networks) en general. En aquest context, el nostre objectiu inicial ha estat analitzar com aquests protocols de senyalització multimèdia, dissenyats per a xarxes IP genèriques, es comporten sobre xarxes mòbils 3GPP. Efectivament, l’ús de protocols IP és fonamental de cara a facilitar la interoperabilitat de solucions diferents. Per altra banda, hi ha escenaris a on és possible aprofitar informació de “context” addicional per a millorar el comportament d’aquests protocols en al cas particular de xarxes mòbils. El cos principal del treball de la tesi ha consistit en l’anàlisi i optimització del rendiment dels protocols de senyalització multimèdia SIP i RTSP, i la definició d’arquitectures de desplegament, amb èmfasi en els serveis 3GPP PSS i 3GPP Mission Critical Push-to-Talk (MCPTT). Aquest treball ha estat precedit per una feina d’anàlisi detallada del comportament dels protocols IP, TCP i UDP sobre xarxes 3GPP, que va proporcionar els fonaments adequats per a la posterior tasca d’anàlisi de protocols de senyalització sobre xarxes mòbils. Les contribucions inclouen la proposta de noves optimitzacions per a millorar els procediments d’establiment de sessions de streaming multimèdia, l’anàlisi detallat i optimització del servei de Presència basat en SIP i la definició de nous casos d’ús i exemples de desplegament d’arquitectures optimitzades per al servei 3GPP MCPTT. Aquestes contribucions ha quedat reflectides en un llibre, tres articles publicats en Revistes Internacionals amb índex JCR, 5 articles publicats en Conferències Internacionals, un article publicat en Congrés Nacional i l’adjudicació d’una patent. La tesi proporciona una descripció detallada de totes les contribucions, així com un exhaustiu repàs del seu context, dels principis fonamentals subjacents a totes les contribucions, la seva aplicabilitat a diferents tipus de desplegaments de xarxa (des de 2.5G a 5G), així una presentació detallada de les arquitectures associades definides per organismes com OMA o 3GPP. Finalment també es presenta l’evolució potencial de la tasca de recerca cap a sistemes 5G.Postprint (published version