Search results for "Image"
showing 10 items of 6818 documents
Texture-less Macula Swelling Detection with Multiple Retinal Fundus Images
2011
International audience
Methods and Technologies - Augmented Reality
2017
International audience
Design of low noise and low power photo-receptor for CMOS vision sensor
2016
International audience
The impact of noise estimation on dehazing
2020
International audience; Under haze or fog, the quality of the images is degraded due to the atmosphere, causing the details of the images to be difficult to identify by observers and computer vision systems. Such images contain noise, which is mainly due either to environment (extrinsic noise) or sensor (intrinsic noise). As the transmission of light coming from the scenes' objects is exponentially attenuated and comes quickly down to zero in presence of haze, the noise is greatly amplified at high haze densities and long distances. In order to investigate the importance of the accurate estimation and the removal of noise from hazy images, we used the CHIC (Color Hazy Image for Comparison) …
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…
Analysing texture features from individual observer simulations
2021
We investigated the impact of simulated individual observer colour matching functions (CMFs) on computational texture features. We hypothesised that most humans perceive texture in a similar manner, hence a texture indicator that is the least dependent on individual physiology of human vision would be most likely a potential fit to serve as quantified visually perceived texture. To this end, the following strategy was implemented: hyper-spectral image textures were converted into XYZ images for individual observer CMFs, contrast sensitivity function (CSF) filtering was subsequently applied on the XYZ images for visual simulation. Two types of texture features were extracted from the filtere…
On the appearance of objects and materials: Qualitative analysis of experimental observations
2021
Perception of appearance of different materials and objects is a complex psychophysical phenomenon and its neurophysiological and behavioral mechanisms are far from being fully understood. The various appearance attributes are usually studied separately. In addition, no comprehensive and functional total appearance modelling has been done up-to date. We have conducted experiments using physical objects asking observers to describe the objects and carry out visual tasks. The process has been videotaped and analysed qualitatively using the Grounded Theory Analysis, a qualitative research methodology from social science. In this work, we construct a qualitative model of this data and compare i…
VisNIR pigment mapping and re-rendering of an experimental painting
2021
Pigment mapping allows the classification and estimation of the abundances of pigments in paintings. The information learned becomes extremely important for conservators, who are then able to decide the best strategies in the conservation of the artefacts. When the goal is to restore a painting, it is also important to know what the effects of the newly introduced materials are. To fulfil this purpose, a proper mixing model must be defined. We propose a framework to perform pigment mapping on the hyperspectral image of an experimental painting realised for the occasion, with the goal of rendering a colour image using the concentrations retrieved from the mapping. Contrarily to spectral unmi…
Development of new techniques for super-resolution video sequences : Towards a real-time implementation on Smart Camera
2020
These thesis works are part of an european project aiming to design a very hight resolution (8k) video camera. Within this project our team had the task of working on two technological aspects: (1) the design of a demonstrator carrying out a realtime deconvolution of a video stream coming from a very high resolution camera created by the consortium , (2) the design of a prototype allowing to increase the resolution and the level of detail of video streams from an input resolution of 4k to 8k using Super Resolution (SR) methods. This manuscript mainly presents the work related to the creation of the prototype realizing a Super Resolution method. In order to be able to assess the qualitative …
Adéquation Algorithme architecture : Aspects logiciels, matériels et cognitifs
2008
Les travaux présentés dans le cadre de cette Habilitation à Diriger des Recherches s'inscrivent principalement dans la problématique dite d'" Adéquation Algorithme Architecture ". Ils ont pour objectif commun la mise en œuvre de systèmes matériels et logiciels dédiés à la vision artificielle à fortes contraintes temporelles. Ils se focalisent sur différents aspects cruciaux tels que l'acquisition d'images par des capteurs dédiés, le développement et la programmation d'architectures optimisées de traitement des images et l'implantation d'algorithmes de traitement du signal et d'images en temps réel sur ces architectures.