Search results for "GiST"

Image registration for quality assessment of projection displays

2014

International audience; In the full reference metric based image quality assessment of projection displays, it is critical to achieve accurate and fully automatic image registration between the captured projection and its reference image in order to establish a subpixel level mapping. The preservation of geometrical order as well as the intensity and chromaticity relationships between two consecutive pixels must be maximized. The existing camera based image registration methods do not meet this requirement well. In this paper, we propose a markerless and view independent method to use an un-calibrated camera to perform the task. The proposed method including three main components: feature e…

Integration of 3D and multispectral data for cultural heritage applications: Survey and perspectives

2013

International audience; Cultural heritage is increasingly put through imaging systems such as multispectral cameras and 3D scanners. Though these acquisition systems are often used independently, they collect complementary information (spectral vs. spatial) used for the study, archiving and visualization of cultural heritage. Recording 3D and multispectral data in a single coordinate system enhances the potential insights in data analysis. Wepresent the state of the art of such acquisition systems and their applications for the study of cultural her- itage. Wealso describe existing registration techniques that can be used to obtain 3D models with multispec- tral texture and explore the idea…

Asserting the Precise Position of 3D and Multispectral Acquisition Systems for Multisensor Registration Applied to Cultural Heritage Analysis

2012

International audience; We present a novel method to register multispectral acquisitions on a 3D model. The method is based on the external tracking of the acquisition systems using close-range photogrammetric techniques: multiple calibrated cameras simultaneously observe the successive acquisition systems in use. The views from these cameras are used to precisely determine the position of each acquisition system. All datasets can then be projected in the same coordinate system. The registration is thus independent from the quality and content of the data. This method is well suited to the study of cultural heritage or any other application where we do not wish to place targets on the objec…

Registration of 3D and Multispectral Data for the Study of Cultural Heritage Surfaces

2013

International audience; We present a technique for the multi-sensor registration of featureless datasets based on the photogrammetric tracking of the acquisition systems in use. This method is developed for the in situ study of cultural heritage objects and is tested by digitizing a small canvas successively with a 3D digitization system and a multispectral camera while simultaneously tracking the acquisition systems with four cameras and using a cubic target frame with a side length of 500 mm. The achieved tracking accuracy is better than 0.03 mm spatially and 0.150 mrad angularly. This allows us to seamlessly register the 3D acquisitions and to project the multispectral acquisitions on th…

L'estimation de trends logistiques : une approche nouvelle d'un thème ancien

1980

Statistical atlas based exudate segmentation

2013

International audience; Diabetic macular edema (DME) is characterized by hard exudates. In this article, we propose a novel statistical atlas based method for segmentation of such exudates. Any test fundus image is first warped on the atlas co-ordinate and then a distance map is obtained with the mean atlas image. This leaves behind the candidate lesions. Post-processing schemes are introduced for final segmentation of the exudate. Experiments with the publicly available HEI-MED data-set shows good performance of the method. A lesion localization fraction of 82.5% at 35% of non-lesion localization fraction on the FROC curve is obtained. The method is also compared to few most recent referen…

Adaptive Hardware Implementation for the Deblocking Filter Used in H.264/AVC Using System GeneratorEnter title

2016

International audience; Xilinx System Generator is a Matlab/Simulink high-level based design tool especially for the development of complex digital circuits using Hardware Description Language (HDL). In this paper we propose a high level model for the deblocking filter used in H.264/AVC using System Generator of Matlab/Simulink. Synthesis results are compared with implementations realized using RTL level. The proposed model allows for rapid edits of the architectures and permits the implementation of filters used in other standards and norms (HEVC for example). The proposed implementations are verified using Xilinx-Virtex5 platforms.

A paleontological viewpoint on the "6th mass exinction".

2020

Editorial. L’agroécologie, une science, un concept, des pratiques culturales, un mouvement politique. Bref historique

2020

International audience; Le terme « agroécologie » s’adresse à la fois à une science, un concept, des pratiques culturales et des mouvements politiques. Il existe de nombreuses définitions de l’agroécologie qui varient d’une institution et d’un pays à l’autre. À la fin des années 1920, la tentative de fusionner l’agronomie et l’écologie est née avec le développement du domaine de l’écologie des cultures dont la principale préoccupation était d’associer des conditions optimales de culture avec la géographie des territoires. L’agronome américain B.M. Bensin est le premier à avoir publié le terme « agroécologie » en 1928. Jusque dans les années 60, le terme agroécologie faisait uniquement référ…

A partial review of cure models with an application to French cancer registries data to improve patients' access to insurance and credit

2016

International audience; BackgroundSurvival cure models are widely used in public health researches to analyze time-to-event data in which some subjects would never experience the event of interest; these subjects are said to be statistically cured. There are two types of cure models, the mixture cure modeland the non-mixture cure model which were first formulated respectively by Boag(1949)[1] and Yakovlev et al. (1993) [2]. These models have been intensively developed [3,4 among others] and have also been extended to the net survival framework [5-7 for instance].In cancersurvival analysis,net survival is a measure of survival in the hypothetical world wherecancer would bethe only possible c…