Robust temporal depth enhancement method for dynamic virtual view synthesis

Depth-image-based rendering (DIBR) is a view synthesis technique that generates virtual views by warping from the reference images based on depth maps. The quality of synthesized views highly depends on the accuracy of depth maps. However, for dynamic scenarios, depth sequences obtained through stereo matching methods frame by frame can be temporally inconsistent, especially in static regions, which leads to uncomfortable flickering artifacts in synthesized videos. This problem can be eliminated by depth enhancement methods that perform temporal filtering to suppress depth inconsistency, yet those methods may also spread depth errors. Although these depth enhancement algorithms increase the temporal consistency of synthesized videos, they have the risk of reducing the quality of rendered videos. Since conventional methods may not achieve both properties, in this paper, we present for static regions a robust temporal depth enhancement (RTDE) method, which propagates exactly the reliable depth values into succeeding frames to upgrade not only the accuracy but also the temporal consistency of depth estimations. This technique benefits the quality of synthesized videos. In addition we propose a novel evaluation metric to quantitatively compare temporal consistency between our method and the state of arts. Experimental results demonstrate the robustness of our method for dynamic virtual view synthesis, not only the temporal consistency but also the quality of synthesized videos in static regions are improved

Analyse d'images aériennes haute résolution pour l'extraction du bâti

Nous présentons dans cet article une méthode pour la détection et la localisation de bâtiments dans un couple d'images aériennes à haute résolution. La méthode s'appuie sur un appariement stéréoscopique multirésolutions et un groupement perceptuel de segments de droite intégrant des informations 3-D

Analyses of stone surfaces by optical methods

Ornamental stone products are generally used for decorative cladding. A major quality parameter is their aesthetical appearance, which directly impacts their commercial value. The surface quality of stone products depends on the presence of defects both due to the unpredictability of natural materials and to the actual manufacturing process. This work starts reviewing the literature about optical methods for stone surface inspection. A classification is then proposed focusing on their industrial applicability in order to provide a guideline for future investigations. Three innovative systems are proposed and described in details: a vision system, an optical profilometer and a reflectometer for the inspection of polished, bush-hammered, sand-blasted, flame-finished, waterjet processed, and laser engraved surfaces

Choquet Fuzzy Integral Applied to Stereovision Matching for Fish-Eye Lenses in Forest Analysis

This paper describes a novel stereovision matching approach based on omni-directional images obtained with fish-eye lenses in forest environments. The goal is to obtain a disparity map as a previous step for determining the volume of wood in the imaged area. The interest is focused on the trunks of the trees, due to the irregular distribution of the trunks; the most suitable features are the pixels. A set of six attributes is used for establishing the matching between the pixels in both images of the stereo pair. The final decision about the matched pixel is taken based on the Choquet Fuzzy Integral paradigm, which is a technique well tested for combining classifiers. The use and adjusting of this decision approach to our specific stereo vision matching problem makes the main finding of the paper. The procedure is based on the application of three well known matching constraints. The proposed approach is compared favourably against the usage of simple features and other fuzzy strategy that combines the simple ones