Applications of image-based, multi-view stereo reconstruction methods = (Aplicaciones de los m��todos de reconstrucci��n est��reo multivista)

These slides present several 3-D reconstruction methods to obtain the geometric structure of a scene that is viewed by multiple cameras. We focus on the combination of the geometric modeling in the image formation process with the use of standard optimization tools to estimate the characteristic parameters that describe the geometry of the 3-D scene. In particular, linear, non-linear and robust methods to estimate the monocular and epipolar geometry are introduced as cornerstones to generate 3-D reconstructions with multiple cameras. Some examples of systems that use this constructive strategy are Bundler, PhotoSynth, VideoSurfing, etc., which are able to obtain 3-D reconstructions with several hundreds or thousands of cameras. En esta presentaci��n se tratan varios m��todos de reconstrucci��n 3-D para la obtenci��n de la estructura geom��trica de una escena que es visualizada por varias c��maras. Se enfatiza la combinaci��n de modelado geom��trico del proceso de formaci��n de la imagen con el uso de herramientas est��ndar de optimizaci��n para estimar los par��metros caracter��sticos que describen la geometr��a de la escena 3-D. En concreto, se presentan m��todos de estimaci��n lineales, no lineales y robustos de las geometr��as monocular y epipolar como punto de partida para generar reconstrucciones con tres o m��s c��maras. Algunos ejemplos de sistemas que utilizan este enfoque constructivo son Bundler, PhotoSynth, VideoSurfing, etc., los cuales, en la pr��ctica pueden llegar a reconstruir una escena con varios cientos o miles de c��maras.

Scalable Raid Storage Based on the Structure of Multimedia File.

In professional video production, users have to access to huge multimedia files simultaneously in an error-free environment, this restriction force the use of expensive disk architectures for video servers. Previous researches proposed different RAID systems for each specific task (ingest, editing, file, play-out, etc.). Video production companies have to acquire different servers with different RAIDs systems in order to support each task in the production workflow. The solution has multiples disadvantages, duplicated material in several RAIDs, duplicated material for different qualities, transfer and transcoding processes, etc. In this work, an architecture for video servers based on the spreading of JPEG200 data in different RAIDs is presented, each individual part of the data structure goes to a specific RAID type depending on the effect that produces the data on the overall image quality, the method provide a redundancy correlated with the data rank. The global storage can be used in all the different tasks of the production workflow saving disk space, redundant files and transfers procedures.

Remote Delivery of Video Services over video links

The spreading of new systems of broadcasting and distribution of multimedia content has had as a consequence a larger need for aggregation of data and metadata to traditionally based contents of video and audio supply. Broadcasting chains of this type of channels have become overwhelmed by the quantity of resources, infrastructures and development needed for these channels to provide information. In order to avoid this kind of shortcomings, several recommendations and standards have been created to exchange metadata between production and distribution of taped programs. The problem lies in live programs, producers sometimes offer data to channels but most often, channels are not able to face required developments. The key to this problem is cost reduction. In this work, a study is conducted on added services which producers may provide to the media about content; a system is found by which additional communication expenses are not made and a model of information transfer is offered which allows low cost developments to supply new media platforms.

Perfect imaging of three object points with only two analytic lens surfaces in two dimensions

In this work, a new two-dimensional analytic optics design method is presented that enables the coupling of three ray sets with two lens profiles. This method is particularly promising for optical systems designed for wide field of view and with clearly separated optical surfaces. However, this coupling can only be achieved if different ray sets will use different portions of the second lens profile. Based on a very basic example of a single thick lens, the Simultaneous Multiple Surfaces design method in two dimensions (SMS2D) will help to provide a better understanding of the practical implications on the design process by an increased lens thickness and a wider field of view. Fermat?s principle is used to deduce a set of functional differential equations fully describing the entire optical system. The transformation of these functional differential equations into an algebraic linear system of equations allows the successive calculation of the Taylor series coefficients up to an arbitrary order. The evaluation of the solution space reveals the wide range of possible lens configurations covered by this analytic design method. Ray tracing analysis for calculated 20th order Taylor polynomials demonstrate excellent performance and the versatility of this new analytical optics design concept.

An attitude-based reasoning strategy to enhance interaction with augmented objects

This paper describes a mobile-based system to interact with objects in smart spaces, where the offer of resources may be extensive. The underlying idea is to use the augmentation capabilities of the mobile device to enable it as user-object mediator. In particular, the paper details how to build an attitude-based reasoning strategy that facilitates user-object interaction and resource filtering. The strategy prioritizes the available resources depending on the spatial history of the user, his real-time location and orientation and, finally, his active touch and focus interactions with the virtual overlay. The proposed reasoning method has been partially validated through a prototype that handles 2D and 3D visualization interfaces. This framework makes possible to develop in practice the IoT paradigm, augmenting the objects without physically modifying them.

Towards a lightweight mobile semantic-based approach for enhancing interaction with smart objects

This work describes a semantic extension for a user-smart object interaction model based on the ECA paradigm (Event-Condition-Action). In this approach, smart objects publish their sensing (event) and action capabilities in the cloud and mobile devices are prepared to retrieve them and act as mediators to configure personalized behaviours for the objects. In this paper, the information handled by this interaction system has been shaped according several semantic models that, together with the integration of an embedded ontological and rule-based reasoner, are exploited in order to (i) automatically detect incompatible ECA rules configurations and to (ii) support complex ECA rules definitions and execution. This semantic extension may significantly improve the management of smart spaces populated with numerous smart objects from mobile personal devices, as it facilitates the configuration of coherent ECA rules.

Quantity and degree assessment in an RDF.based semantic language

This paper introduces a semantic language developed with the objective to be used in a semantic analyzer based on linguistic and world knowledge. Linguistic knowledge is provided by a Combinatorial Dictionary and several sets of rules. Extra-linguistic information is stored in an Ontology. The meaning of the text is represented by means of a series of RDF-type triples of the form predicate (subject, object). Semantic analyzer is one of the options of the multifunctional ETAP-3 linguistic processor. The analyzer can be used for Information Extraction and Question Answering. We describe semantic representation of expressions that provide an assessment of the number of objects involved and/or give a quantitative evaluation of different types of attributes. We focus on the following aspects: 1) parametric and non-parametric attributes; 2) gradable and non-gradable attributes; 3) ontological representation of different classes of attributes; 4) absolute and relative quantitative assessment; 5) punctual and interval quantitative assessment; 6) intervals with precise and fuzzy boundaries

Adaptive neuro-fuzzy inference systems (ANFIS) for supervised classification of competence in MIS based on psychomotor skills

INTRODUCTION: Objective assessment of motor skills has become an important challenge in minimally invasive surgery (MIS) training.Currently, there is no gold standard defining and determining the residents' surgical competence.To aid in the decision process, we analyze the validity of a supervised classifier to determine the degree of MIS competence based on assessment of psychomotor skills METHODOLOGY: The ANFIS is trained to classify performance in a box trainer peg transfer task performed by two groups (expert/non expert). There were 42 participants included in the study: the non-expert group consisted of 16 medical students and 8 residents (< 10 MIS procedures performed), whereas the expert group consisted of 14 residents (> 10 MIS procedures performed) and 4 experienced surgeons. Instrument movements were captured by means of the Endoscopic Video Analysis (EVA) tracking system. Nine motion analysis parameters (MAPs) were analyzed, including time, path length, depth, average speed, average acceleration, economy of area, economy of volume, idle time and motion smoothness. Data reduction was performed by means of principal component analysis, and then used to train the ANFIS net. Performance was measured by leave one out cross validation. RESULTS: The ANFIS presented an accuracy of 80.95%, where 13 experts and 21 non-experts were correctly classified. Total root mean square error was 0.88, while the area under the classifiers' ROC curve (AUC) was measured at 0.81. DISCUSSION: We have shown the usefulness of ANFIS for classification of MIS competence in a simple box trainer exercise. The main advantage of using ANFIS resides in its continuous output, which allows fine discrimination of surgical competence. There are, however, challenges that must be taken into account when considering use of ANFIS (e.g. training time, architecture modeling). Despite this, we have shown discriminative power of ANFIS for a low-difficulty box trainer task, regardless of the individual significances between MAPs. Future studies are required to confirm the findings, inclusion of new tasks, conditions and sample population.

A hierarchical strategy for real-time tracking on-board UAVs

In this paper, we present a real-time tracking strategy based on direct methods for tracking tasks on-board UAVs, that is able to overcome problems posed by the challenging conditions of the task: e.g. constant vibrations, fast 3D changes, and limited capacity on-board. The vast majority of approaches make use of feature-based methods to track objects. Nonetheless, in this paper we show that although some of these feature-based solutions are faster, direct methods can be more robust under fast 3D motions (fast changes in position), some changes in appearance, constant vibrations (without requiring any specific hardware or software for video stabilization), and situations where part of the object to track is out the field of view of the camera. The performance of the proposed strategy is evaluated with images from real-flight tests using different evaluation mechanisms (e.g. accurate position estimation using a Vicon sytem). Results show that our tracking strategy performs better than well known feature-based algorithms and well known configurations of direct methods, and that the recovered data is robust enough for vision-in-the-loop tasks.

Power management techniques in an FPGA-Based WSN node for high performance application

In this work, the power management techniques implemented in a high-performance node for Wireless Sensor Networks (WSN) based on a RAM-based FPGA are presented. This new node custom architecture is intended for high-end WSN applications that include complex sensor management like video cameras, high compute demanding tasks such as image encoding or robust encryption, and/or higher data bandwidth needs. In the case of these complex processing tasks, yet maintaining low power design requirements, it can be shown that the combination of different techniques such as extensive HW algorithm mapping, smart management of power islands to selectively switch on and off components, smart and low-energy partial reconfiguration, an adequate set of save energy modes and wake up options, all combined, may yield energy results that may compete and improve energy usage of typical low power microcontrollers used in many WSN node architectures. Actually, results show that higher complexity tasks are in favor of HW based platforms, while the flexibility achieved by dynamic and partial reconfiguration techniques could be comparable to SW based solutions.

A Multingual Web-based Educational System for Professional Musicians

This paper presents the main results of the eContent HARMOS project. The project has developed a webbased educational system for professional musicians. The main idea of the project consists of recording master classes taught by highly recognised maestros and annotate this multimedia material using an educational musical taxonomy and automatic annotation tools. Users of the system access a multi-criteria search engine that allows them to find and play video segments according to a combination of criteria, which include instrument, teacher, composer, composition, movement and pedagogical concept. In order to preserve teachers and students rights, a DRM and protection system has been developed. The system is being publicly exploited. This model preserves musical heritage, since these valuable master classes are usually not recorded and it also provides a sustainable model for musical institutions.

Modelado en alto nivel con SystemC

El presente proyecto final de carrera titulado ���Modelado de alto nivel con SystemC��� tiene como objetivo principal el modelado de algunos m��dulos de un codificador de v��deo MPEG-2 utilizando el lenguaje de descripci��n de sistemas igitales SystemC con un nivel de abstracci��n TLM o Transaction Level Modeling. SystemC es un lenguaje de descripci��n de sistemas digitales basado en C++. En ��l hay un conjunto de rutinas y librer��as que implementan tipos de datos, estructuras y procesos especiales para el modelado de sistemas digitales. Su descripci��n se puede consultar en [GLMS02] El nivel de abstracci��n TLM se caracteriza por separar la comunicaci��n entre los m��dulos de su funcionalidad. Este nivel de abstracci��n hace un mayor ��nfasis en la funcionalidad de la comunicaci��n entre los m��dulos (de donde a donde van datos) que la implementaci��n exacta de la misma. En los documentos [RSPF] y [HG] se describen el TLM y un ejemplo de implementaci��n. La arquitectura del modelo se basa en el codificador MVIP-2 descrito en [Gar04], de dicho modelo, los m��dulos implementados son: �� IVIDEOH: m��dulo que realiza un filtrado del v��deo de entrada en la dimensi��n horizontal y guarda en memoria el video filtrado. �� IVIDEOV: m��dulo que lee de la memoria el v��deo filtrado por IVIDEOH, realiza el filtrado en la dimensi��n horizontal y escribe el video filtrado en memoria. �� DCT: m��dulo que lee el video filtrado por IVIDEOV, hace la transformada discreta del coseno y guarda el v��deo transformado en la memoria. �� QUANT: m��dulo que lee el video transformado por DCT, lo cuantifica y guarda el resultado en la memoria. �� IQUANT: m��dulo que lee el video cuantificado por QUANT, realiza la cuantificaci��n inversa y guarda el resultado en memoria. �� IDCT: m��dulo que lee el video procesado por IQUANT, realiza la transformada inversa del coseno y guarda el resultado en memoria. �� IMEM: m��dulo que hace de interfaz entre los m��dulos anteriores y la memoria. Gestiona las peticiones simult��neas de acceso a la memoria y asegura el acceso exclusivo a la memoria en cada instante de tiempo. Todos estos m��dulos aparecen en gris en la siguiente figura en la que se muestra la arquitectura del modelo: Figura 1. Arquitectura del modelo (VER PDF DEL PFC) En figura tambi��n aparecen unos m��dulos en blanco, dichos m��dulos son de pruebas y se han a��adido para realizar simulaciones y probar los m��dulos del modelo: �� CAMARA: m��dulo que simula una c��mara en blanco y negro, lee la luminancia de un fichero de v��deo y lo env��a al modelo a trav��s de una FIFO. �� FIFO: hace de interfaz entre la c��mara y el modelo, guarda los datos que env��a la c��mara hasta que IVIDEOH los lee. �� CONTROL: m��dulo que se encarga de controlar los m��dulos que procesan el v��deo, estos le indican cuando terminan de procesar un frame de v��deo y este m��dulo se encarga de iniciar los m��dulos que sean necesarios para seguir con la codificaci��n. Este m��dulo se encarga del correcto secuenciamiento de los m��dulos procesadores de v��deo. �� RAM: m��dulo que simula una memoria RAM, incluye un retardo programable en el acceso. Para las pruebas tambi��n se han generado ficheros de v��deo con el resultado de cada m��dulo procesador de v��deo, ficheros con mensajes y un fichero de trazas en el que se muestra el secuenciamiento de los procesadores. Como resultado del trabajo en el presente PFC se puede concluir que SystemC permite el modelado de sistemas digitales con bastante sencillez (hace falta conocimientos previos de C++ y programaci��n orientada objetos) y permite la realizaci��n de modelos con un nivel de abstracci��n mayor a RTL, el habitual en Verilog y VHDL, en el caso del presente PFC, el TLM. ABSTRACT This final career project titled ���High level modeling with SystemC��� have as main objective the modeling of some of the modules of an MPEG-2 video coder using the SystemC digital systems description language at the TLM or Transaction Level Modeling abstraction level. SystemC is a digital systems description language based in C++. It contains routines and libraries that define special data types, structures and process to model digital systems. There is a complete description of the SystemC language in the document [GLMS02]. The main characteristic of TLM abstraction level is that it separates the communication among modules of their functionality. This abstraction level puts a higher emphasis in the functionality of the communication (from where to where the data go) than the exact implementation of it. The TLM and an example are described in the documents [RSPF] and [HG]. The architecture of the model is based in the MVIP-2 video coder (described in the document [Gar04]) The modeled modules are: �� IVIDEOH: module that filter the video input in the horizontal dimension. It saves the filtered video in the memory. �� IVIDEOV: module that read the IVIDEOH filtered video, filter it in the vertical dimension and save the filtered video in the memory. �� DCT: module that read the IVIDEOV filtered video, do the discrete cosine transform and save the transformed video in the memory. �� QUANT: module that read the DCT transformed video, quantify it and save the quantified video in the memory. �� IQUANT: module that read the QUANT processed video, do the inverse quantification and save the result in the memory. �� IDCT: module that read the IQUANT processed video, do the inverse cosine transform and save the result in the memory. �� IMEM: this module is the interface between the modules described previously and the memory. It manage the simultaneous accesses to the memory and ensure an unique access at each instant of time All this modules are included in grey in the following figure (SEE PDF OF PFC). This figure shows the architecture of the model: Figure 1. Architecture of the model This figure also includes other modules in white, these modules have been added to the model in order to simulate and prove the modules of the model: �� CAMARA: simulates a black and white video camera, it reads the luminance of a video file and sends it to the model through a FIFO. �� FIFO: is the interface between the camera and the model, it saves the video data sent by the camera until the IVIDEOH module reads it. �� CONTROL: controls the modules that process the video. These modules indicate the CONTROL module when they have finished the processing of a video frame. The CONTROL module, then, init the necessary modules to continue with the video coding. This module is responsible of the right sequence of the video processing modules. �� RAM: it simulates a RAM memory; it also simulates a programmable delay in the access to the memory. It has been generated video files, text files and a trace file to check the correct function of the model. The trace file shows the sequence of the video processing modules. As a result of the present final career project, it can be deduced that it is quite easy to model digital systems with SystemC (it is only needed previous knowledge of C++ and object oriented programming) and it also allow the modeling with a level of abstraction higher than the RTL used in Verilog and VHDL, in the case of the present final career project, the TLM.

Popularity based distribution schemes for P2P assisted streaming of VoD contents

The Video on Demand (VoD) service is becoming a dominant service in the telecommunication market due to the great convenience regarding the choice of content items and their independent viewing time. However, it comes with the downsides of high server storage and capacity demands because of the large variety of content items and the high amount of traffic generated for serving all requests. Storing part of the popular contents on the peers brings certain advantages but, it still has issues regarding the overall traffic in the core of the network and the scalability. Therefore, we propose a P2P assisted model for streaming VoD contents that takes advantage of the clients unused uplink and storage capacity to serve requests of other clients and we present popularity based schemes for distribution of both the popular and unpopular contents on the peers. The proposed model and the schemes prove to reduce the streaming traffic in the core of the network, improve the responsiveness of the system and increase its scalability.

Methodologies for implement video decoders over multiprocessor platforms

The latest video coding standards developed, like HEVC (High Efficiency Video Coding, approved in January 2013), require for their implementation the use of devices able to support a high computational load. Considering that currently it is not enough the usage of one unique Digital Signal Processor (DSP), multicore devices have appeared recently in the market. However, due to its novelty, the working methodology that allows produce solutions for these configurations is in a very initial state, since currently the most part of the work needs to be performed manually. In consequence, the objective set consists on finding methodologies that ease this process. The study has been focused on extend a methodology, under development, for the generation of solutions for PCs and embedded systems. During this study, the standards RVC (Reconfigurable Video Coding) and HEVC have been employed, as well as DSPs of the Texas Instruments company. In its development, it has been tried to address all the factors that influence both the development and deployment of these new implementations of video decoders, ranging from tools up to aspects of the partitioning of algorithms, without this can cause a drop in application performance. The results of this study are the description of the employed methodology, the characterization of the software migration process and performance measurements for the HEVC standard in an RVC-based implementation. RESUMEN Los est��ndares de codificaci��n de v��deo desarrollados m��s recientemente, como HEVC (High Efficiency Video Coding, aprobado en enero de 2013), requieren para su implementaci��n el uso de dispositivos capaces de soportar una elevada carga computacional. Teniendo en cuenta que actualmente no es suficiente con utilizar un ��nico Procesador Digital de Se��al (DSP), han aparecido recientemente dispositivos multin��cleo en el mercado. Sin embargo, debido a su novedad, la metodolog��a de trabajo que permite elaborar soluciones para tales configuraciones se encuentra en un estado muy inicial, ya que actualmente la mayor parte del trabajo debe realizarse manualmente. En consecuencia, el objetivo marcado consiste en encontrar metodolog��as que faciliten este proceso. El estudio se ha centrado en extender una metodolog��a, en desarrollo, para la generaci��n de soluciones para PC y sistemas empotrados. Durante dicho estudio se han empleado los est��ndares RVC (Reconfigurable Video Coding) y HEVC, as�� como DSPs de la compa����a Texas Instruments. En su desarrollo se ha tratado de atender a todos los factores que influyen tanto en el desarrollo como en la puesta en marcha de estas nuevas implementaciones de descodificadores de v��deo; abarcando desde las herramientas a utilizar hasta aspectos del particionado de los algoritmos, sin que por ello se produzca una reducci��n en el rendimiento de las aplicaciones. Los resultados de este estudio son una descripci��n de la metodolog��a empleada, la caracterizaci��n del proceso de migraci��n de software, y medidas de rendimiento para el est��ndar HEVC en una implementaci��n basada en RVC.

Implementation of wireless communication based on Software Defined Radio

In current communication systems, there are many new challenges like various competitive standards, the scarcity of frequency resource, etc., especially the development of personal wireless communication systems result the new system update faster than ever before, the conventional hardware-based wireless communication system is difficult to adapt to this situation. The emergence of SDR enabled the third revolution of wireless communication which from hardware to software and build a flexible, reliable, upgradable, reusable, reconfigurable and low cost platform. The Universal Software Radio Peripheral (USRP) products are commonly used with the GNU Radio software suite to create complex SDR systems. GNU Radio is a toolkit where digital signal processing blocks are written in C++, and connected to each other with Python. This makes it easy to develop more sophisticated signal processing systems, because many blocks already written by others and you can quickly put them together to create a complete system. Although the main function of GNU Radio is not be a simulator, but if there is no RF hardware components,it supports to researching the signal processing algorithm based on pre-stored and generated data by signal generator. This thesis introduced SDR platform from hardware (USRP) and software(GNU Radio), as well as some basic modulation techniques in wireless communication system. Based on the examples provided by GNU Radio, carried out some related experiments, for example GSM scanning and FM radio station receiving on USRP. And make a certain degree of improvement based on the experience of some investigators to observe OFDM spectrum and simulate real-time video transmission. GNU Radio combine with USRP hardware proved to be a valuable lab platform for implementing complex radio system prototypes in a short time. RESUMEN. Software Defined Radio (SDR) es una tecnolog��a emergente que est�� creando un impacto revolucionario en la tecnolog��a de radio convencional. Un buen ejemplo de radio software son los sistemas de c��digo abierto llamados GNU Radio que emplean un kit de herramientas de desarrollo de software libre. En este trabajo se ha empleado un kit de desarrollo comercial (Ettus Research) que consiste en un m��dulo de procesado de se��al y un hardaware sencillo. El m��dulo emplea un software de desarrollo basado en Linux sobre el que se pueden implementar aplicaciones de radio software muy variadas. El hardware de desarrollo consta de un microprocesador de prop��sito general, un dispositivo programable (FPGA) y un interfaz de radiofrecuencia que cubre de 50 a 2200MHz. Este hardware se conecta al PC por medio de un interfaz USB de 8Mb/s de velocidad. Sobre la plataforma de Ettus se pueden ejecutar aplicaciones GNU radio que utilizan principalmente lenguaje de programaci��n Python para implementarse. Sin embargo, su m��dulo de procesado de se��al est�� construido en C + + y emplea un microprocesador con aritm��tica de coma flotante. Por lo tanto, los desarrolladores pueden r��pida y f��cilmente construir aplicaciones en tiempo real sistemas de comunicaci��n inal��mbrica de alta capacidad. Aunque su funci��n principal no es ser un simulador, si no puesto que hay componentes de hardware RF, Radio GNU sirve de apoyo a la investigaci��n del algoritmo de procesado de se��ales basado en pre-almacenados y generados por los datos del generador de se��al. En este trabajo fin de m��ster se ha evaluado la plataforma de hardware de DEG (USRP) y el software (GNU Radio). Para ello se han empleado algunas t��cnicas de modulaci��n b��sicas en el sistema de comunicaci��n inal��mbrica. A partir de los ejemplos proporcionados por GNU Radio, hemos realizado algunos experimentos relacionados, por ejemplo, escaneado del espectro, demodulaci��n de se��ales de FM empleando siempre el hardware de USRP. Una vez evaluadas aplicaciones sencillas se ha pasado a realizar un cierto grado de mejora y optimizaci��n de aplicaciones complejas descritas en la literatura. Se han empleado aplicaciones como la que consiste en la generaci��n de un espectro de OFDM y la simulaci��n y transmisi��n de se��ales de v��deo en tiempo real. Con estos resultados se est�� ahora en disposici��n de abordar la elaboraci��n de aplicaciones complejas.