Coding of details in very low bit-rate video systems

In this paper, the importance of including small image features at the initial levels of a progressive second generation video coding scheme is presented. It is shown that a number of meaningful small features called details should be coded, even at very low data bit-rates, in order to match their perceptual significance to the human visual system. We propose a method for extracting, perceptually selecting and coding of visual details in a video sequence using morphological techniques. Its application in the framework of a multiresolution segmentation-based coding algorithm yields better results than pure segmentation techniques at higher compression ratios, if the selection step fits some main subjective requirements. Details are extracted and coded separately from the region structure and included in the reconstructed images in a later stage. The bet of considering the local background of a given detail for its perceptual selection breaks the concept ofPeer ReviewedPostprint (published version

New metric products, movies and 3D models from old stereopairs and their application to the in situ palaeontological site of Ambrona

[ES] Este artículo está basado en la información del siguiente proyecto:● LDGP_mem_006-1: "[S_Ambrona_Insitu] Levantamiento fotogramétrico del yacimiento paleontológico “Museo in situ” de Ambrona (Soria)", http://hdl.handle.net/10810/7353● LDGP_mem_006-1: "[S_Ambrona_Insitu] Levantamiento fotogramétrico del yacimiento paleontológico “Museo in situ” de Ambrona (Soria)", http://hdl.handle.net/10810/7353[EN] This paper is based on the information gathered in the following project:[EN] 3D modelling tools from photographic pictures have experienced significant improvements in the last years. One of the most outstanding changes is the spread of the photogrammetric systems based on algorithms referred to as Structure from Motion (SfM) in contrast with the traditional stereoscopic pairs. Nevertheless, the availability of important collections of stereoscopic registers collected during past decades invites us to explore the possibilities for re-using these photographs in order to generate new multimedia products, especially due to the fact that many of the documented elements have been largely altered or even disappeared. This article analyses an example of application to the re-use of a collection of photographs from the palaeontological site of Ambrona (Soria, Spain). More specifically, different pieces of software based on Structure from Motion (SfM) algorithms for the generation of 3D models with photographic textures are tested and some derived products such as orthoimages, video or applications of Augmented Reality (AR) are presented.[ES] Las herramientas de modelado 3D a partir de imágenes fotográficas han experimentado avances muy significativos en los últimos años. Uno de los más destacados corresponde a la generalización de los sistemas fotogramétricos basados en los algoritmos denominados Structure from Motion (SfM) sobre los proyectos de documentación tradicional basados en pares estereoscópicos. La existencia de importantes colecciones de registros estereoscópicos realizados durante las décadas anteriores invita a explorar las posibilidades de reutilización de estos registros para la obtención de productos multimedia actuales, máxime cuando algunos de los elementos documentados han sufrido grandes modificaciones o incluso desaparecido. En el presente artículo se analiza la reutilización de colecciones fotográficas de yacimientos paleontológicos mediante un ejemplo centrado en el yacimiento de Ambrona (Soria, España). En concreto, se contrastan varios programas basados en los algoritmos denominados Structure from Motion (SfM) para la generación del modelo 3D con textura y otros productos derivados como ortoimágenes, vídeos o aplicaciones de Realidad Aumentada (RA)

A morphological approach for segmentation and tracking of human faces

A new technique for segmenting and tracking human faces in video sequences is presented. The technique relies on morphological tools such as using connected operators to extract the connected component that more likely belongs to a face, and partition projection to track this component through the sequence. A binary partition tree (BPT) is used to implement the connected operator. The BPT is constructed based on the chrominance criteria and its nodes are analyzed so that the selected node maximizes an estimation of the likelihood of being part of a face. The tracking is performed using a partition projection approach. Images are divided into face and non-face parts, which are tracked through the sequence. The technique has been successfully assessed using several test sequences from the MPEG-4 (raw format) and the MPEG-7 databases (MPEG-1 format).Peer ReviewedPostprint (published version

Perception for detection and grasping

The final publication is available at link.springer.comThis research presents a methodology for the detection of the crawler used in the project AEROARMS. The approach consisted on using a two-step progressive strategy, going from rough detection and tracking, for approximation maneuvers, to an accurate positioning step based on fiducial markers. Two different methods are explained for the first step, one using efficient image segmentation approach; and the second one using Deep Learning techniques to detect the center of the crawler. The fiducial markers are used for precise localization of the crawler in a similar way as explained in earlier chapters. The methods can run in real-time.Peer ReviewedPostprint (author's final draft