Recursos de colección

Archivo Digital UPM (109.492 recursos)

This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Robótica e Informática Industrial

Mostrando recursos 1 - 20 de 444

  1. Bounded non-deterministic planning for multimedia adaptation

    López, Fernando; Jannach, Dietmar; Martinez, Jose Maria; Timmerer, Christian; García Santos, Narciso; Hellwagner, Hermann
    This paper proposes a novel combination of artificial intelligence planning and other techniques for improving decision-making in the context of multi-step multimedia content adaptation. In particular, it describes a method that allows decision-making (selecting the adaptation to perform) in situations where third-party pluggable multimedia conversion modules are involved and the multimedia adaptation planner does not know their exact adaptation capabilities. In this approach, the multimedia adaptation planner module is only responsible for a part of the required decisions; the pluggable modules make additional decisions based on different criteria. We demonstrate that partial decision-making is not only attainable, but also introduces...

  2. Moving object detection for real-time augmented reality applications in a GPGPU

    Cuevas Rodríguez, Carlos; Berjón Díez, Daniel; Morán Burgos, Francisco; García Santos, Narciso
    The last generation of consumer electronic devices is endowed with Augmented Reality (AR) tools. These tools require moving object detection strategies, which should be fast and efficient, to carry out higher level object analysis tasks. We propose a lightweight spatio-temporal-based non-parametric background-foreground modeling strategy in a General Purpose Graphics Processing Unit (GPGPU), which provides real-time high-quality results in a great variety of scenarios and is suitable for AR applications.

  3. Comparación de desempeño de una cámara de profundidad comercial y un LIDAR en explotaciones agrícolas.

    Correa Farias, Christian; Garrido Izard, Miguel; Moya Gonzalez, Adolfo; Valero Ubierna, Constantino; Barreiro Elorza, Pilar
    Este estudio presenta una comparativa entre un LIDAR modelo LMS-111 (Sick Ltd.) y una cámara de profundidad de uso doméstico: Kinect (Microsoft Corporation), orientada a determinar las condiciones de uso de uno y otro sensor, así como sus ventajas e inconvenientes cuando son empleados en condiciones de campo, en una explotación agrícola. Para ello se realizaron diversos ensayos en una parcela experimental del CSIC-CAR de Arganda del Rey, España. Para los ensayos ambos sensores fueron instalados en un tractor operado remotamente diseñado y construido en el marco del proyecto europeo RHEA. Dicho tractor realizó dos recorridos diferentes: el primero se...

  4. A framework for the analysis and optimization of encoding latency for multiview video

    Carballeira López, Pablo; Cabrera Quesada, Julian; Ortega Diego, Antonio; Jaureguizar Núñez, Fernando; García Santos, Narciso
    We present a novel framework for the analysis and optimization of encoding latency for multiview video. Firstly, we characterize the elements that have an influence in the encoding latency performance: (i) the multiview prediction structure and (ii) the hardware encoder model. Then, we provide algorithms to find the encoding latency of any arbitrary multiview prediction structure. The proposed framework relies on the directed acyclic graph encoder latency (DAGEL) model, which provides an abstraction of the processing capacity of the encoder by considering an unbounded number of processors. Using graph theoretic algorithms, the DAGEL model allows us to compute the encoding...

  5. Analysis of pixel-mapping rounding on geometric distortion as a prediction for view synthesis distortion

    Carballeira López, Pablo; Cabrera Quesada, Julian; Ekmekcioglu, E.; Jaureguizar Núñez, Fernando; García Santos, Narciso
    We analyze the performance of the geometric distortion, incurred when coding depth maps in 3D Video, as an estimator of the distortion of synthesized views. Our analysis is motivated by the need of reducing the computational complexity required for the computation of synthesis distortion in 3D video encoders. We propose several geometric distortion models that capture (i) the geometric distortion caused by the depth coding error, and (ii) the pixel-mapping precision in view synthesis. Our analysis starts with the evaluation of the correlation of geometric distortion values obtained with these models and the actual distortion on synthesized views. Then, the...

  6. Low latency LDGM code for multimedia-packet stream in bursty packet loss networks

    Casu, Filippo; Cabrera Quesada, Julian; Jaureguizar Núñez, Fernando; García Santos, Narciso
    In this paper we present a FEC scheme based on simple LDGM codes to protect packetized multimedia streams. We demonstrate that simple LDGM codes working with a limited number of packets (small values of k) obtain recovery capabilities, against bursty packet losses, that are similar to those of other more complex FEC-based schemes designed for this type of channels.

  7. Monitoring packet loss impact in IPTV and 3DTV receivers

    Gutierrez Sanchez, Jesus; Pérez García, Pablo; Jaureguizar Núñez, Fernando; Cabrera Quesada, Julian; García Santos, Narciso
    Considering a scalable video quality monitoring architecture to detect transmission errors at households, we propose a technique to detect packet losses in IPTV and Side-by-Side 3DTV and evaluate their impact on the perceived quality.

  8. Moving object detection strategy for augmented-reality applications in a GPGPU by using CUDA

    Berjón Díez, Daniel; Cuevas Rodríguez, Carlos; Morán Burgos, Francisco; García Santos, Narciso
    A spatial-color-based non-parametric background-foreground modeling strategy in a GPGPU by using CUDA is proposed. This strategy is suitable for augmented-reality applications, providing real-time high-quality results in a great variety of scenarios.

  9. NAMA3DS1-COSPAD1: Subjective video quality assessment database on coding conditions introducing freely available high quality 3D stereoscopic sequences

    Urvoy, Matthieu; Barkowsky, Marcus; Cousseau, Romain; Koudota, Yao; Ricordel, Vincent; Le Callet, Patrick; Gutierrez Sanchez, Jesus; García Santos, Narciso
    Research in stereoscopic 3D coding, transmission and subjective assessment methodology depends largely on the availability of source content that can be used in cross-lab evaluations. While several studies have already been presented using proprietary content, comparisons between the studies are difficult since discrepant contents are used. Therefore in this paper, a freely available dataset of high quality Full-HD stereoscopic sequences shot with a semiprofessional 3D camera is introduced in detail. The content was designed to be suited for usage in a wide variety of applications, including high quality studies. A set of depth maps was calculated from the stereoscopic pair....

  10. Subjective study of adaptive streaming strategies for 3DTV

    Gutierrez Sanchez, Jesus; Pérez García, Pablo; Jaureguizar Núñez, Fernando; Cabrera Quesada, Julian; García Santos, Narciso
    Although the delivery of 3D video services to households is nowadays a reality thanks to frame-compatible formats, many efforts are being made to obtain efficient methods to transmit 3D content offering a high quality of experience to the end users. In this paper, a stereoscopic video streaming scenario is considered and the perceptual impact of various strategies applicable to adaptive streaming situations are compared. Specifically, the mechanisms are based on switching between copies of the content with different coding qualities, on discarding frames of the sequence, on switching from 3D to 2D and on using asymmetric coding of the stereo...

  11. Systematic analysis of the decoding delay on MVC decoders

    Carballeira López, Pablo; Cabrera Quesada, Julian; Jaureguizar Núñez, Fernando; García Santos, Narciso
    We present a framework for the analysis of the decoding delay and communication latency in Multiview Video Coding. The application of this framework on MVC decoders allows minimizing the overall delay in immersive video-conference systems.

  12. Validation of a novel approach to subjective quality evaluation of conventional and 3D broadcasted video services

    Gutierrez Sanchez, Jesus; Pérez García, Pablo; Jaureguizar Núñez, Fernando; Cabrera Quesada, Julian; García Santos, Narciso
    Transmission errors are the main cause of degradation of the quality of real broadcasted video services. Therefore, knowing their impact on the quality of experience of the end users is a crucial issue. For instance, it would help to improve the performance of the distribution systems, and to develop monitoring tools to automatically estimate the quality perceived by the end users. In this paper we validate a subjective evaluation approach specifically designed to obtain meaningful results of the effects of degradations caused by transmission errors. This methodology has been already used in our previous works with monoscopic and stereoscopic videos....

  13. Adaptive protection scheme for MVC-encoded stereoscopic video streaming in IP-based networks

    Díaz Martín, César; Cabrera Quesada, Julian; Jaureguizar Núñez, Fernando; García Santos, Narciso
    We present an adaptive unequal error protection (UEP) strategy built on the 1-D interleaved parity Application Layer Forward Error Correction (AL-FEC) code for protecting the transmission of stereoscopic 3D video content encoded with Multiview Video Coding (MVC) through IP-based networks. Our scheme targets the minimization of quality degradation produced by packet losses during video transmission in time-sensitive application scenarios. To that end, based on a novel packet-level distortion model, it selects in real time the most suitable packets within each Group of Pictures (GOP) to be protected and the most convenient FEC technique parameters, i.e., the size of the FEC...

  14. 3D facial merging for virtual human reconstruction

    Pages Scasso, Rafael; Morán Burgos, Francisco
    There is an increasing need of easy and affordable technologies to automatically generate virtual 3D models from their real counterparts. In particular, 3D human reconstruction has driven the creation of many clever techniques, most of them based on the visual hull (VH) concept. Such techniques do not require expensive hardware; however, they tend to yield 3D humanoids with realistic bodies but mediocre faces, since VH cannot handle concavities. On the other hand, structured light projectors allow to capture very accurate depth data, and thus to reconstruct realistic faces, but they are too expensive to use several of them. We have...

  15. Accurate depth-color scene modeling for 3D contents generation with low cost depth cameras

    Camplani, Massimo; Mantecón del Valle, Tomás; Salgado Álvarez de Sotomayor, Luis
    In this paper, we present a depth-color scene modeling strategy for indoors 3D contents generation. It combines depth and visual information provided by a low-cost active depth camera to improve the accuracy of the acquired depth maps considering the different dynamic nature of the scene elements. Accurate depth and color models of the scene background are iteratively built, and used to detect moving elements in the scene. The acquired depth data is continuously processed with an innovative joint-bilateral filter that efficiently combines depth and visual information thanks to the analysis of an edge-uncertainty map and the detected foreground regions. The...

  16. Region-dependent vehicle classification using PCA features

    Arróspide Laborda, Jon; Salgado Álvarez de Sotomayor, Luis
    Video-based vehicle detection is the focus of increasing interest due to its potential towards collision avoidance. In particular, vehicle verification is especially challenging due to the enormous variability of vehicles in size, color, pose, etc. In this paper, a new approach based on supervised learning using Principal Component Analysis (PCA) is proposed that addresses the main limitations of existing methods. Namely, in contrast to classical approaches which train a single classifier regardless of the relative position of the candidate (thus ignoring valuable pose information), a region-dependent analysis is performed by considering four different areas. In addition, a study on the...

  17. Traffic sign detection and tracking using robust 3D analysis

    Marinas Mateos, Javier; Salgado Álvarez de Sotomayor, Luis; Arróspide Laborda, Jon; Camplani, Massimo
    In this paper we present an innovative technique to tackle the problem of automatic road sign detection and tracking using an on-board stereo camera. It involves a continuous 3D analysis of the road sign during the whole tracking process. Firstly, a color and appearance based model is applied to generate road sign candidates in both stereo images. A sparse disparity map between the left and right images is then created for each candidate by using contour-based and SURF-based matching in the far and short range, respectively. Once the map has been computed, the correspondences are back-projected to generate a cloud...

  18. Multi-Camera very wide baseline feature matching based on view-adaptive junction detection

    Pérez Rivero, Maykel; Salgado Álvarez de Sotomayor, Luis; Arróspide Laborda, Jon; Marinas Mateos, Javier; Nieto Doncel, Marcos
    This paper presents a strategy for solving the feature matching problem in calibrated very wide-baseline camera settings. In this kind of settings, perspective distortion, depth discontinuities and occlusion represent enormous challenges. The proposed strategy addresses them by using geometrical information, specifically by exploiting epipolar-constraints. As a result it provides a sparse number of reliable feature points for which 3D position is accurately recovered. Special features known as junctions are used for robust matching. In particular, a strategy for refinement of junction end-point matching is proposed which enhances usual junction-based approaches. This allows to compute cross-correlation between perfectly aligned plane patches...

  19. Depth perceptual video coding for free viewpoint video based on H.264/AVC

    Cernigliaro, Gianluca; Naccari, M.; Jaureguizar Núñez, Fernando; Cabrera Quesada, Julian; García Santos, Narciso
    A novel scheme for depth sequences compression, based on a perceptual coding algorithm, is proposed. A depth sequence describes the object position in the 3D scene, and is used, in Free Viewpoint Video, for the generation of synthetic video sequences. In perceptual video coding the human visual system characteristics are exploited to improve the compression efficiency. As depth sequences are never shown, the perceptual video coding, assessed over them, is not effective. The proposed algorithm is based on a novel perceptual rate distortion optimization process, assessed over the perceptual distortion of the rendered views generated through the encoded depth sequences....

  20. High-quality real-time temporal segmentation tool for video editing software

    Cuevas Rodríguez, Carlos; García Santos, Narciso
    The increasing use of video editing software has resulted in a necessity for faster and more efficient editing tools. Here, we propose a lightweight high-quality video indexing tool that is suitable for video editing software.

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