Search results for " Images."
showing 10 items of 193 documents
VAMPIRE: Vessel assessment and measurement platform for images of the REtina
2011
We present VAMPIRE, a software application for efficient, semi-automatic quantification of retinal vessel properties with large collections of fundus camera images. VAMPIRE is also an international collaborative project of four image processing groups and five clinical centres. The system provides automatic detection of retinal landmarks (optic disc, vasculature), and quantifies key parameters used frequently in investigative studies: vessel width, vessel branching coefficients, and tortuosity. The ultimate vision is to make VAMPIRE available as a public tool, to support quantification and analysis of large collections of fundus camera images.
Contribution à l'étude de la formation des images optiques en microscopie champ proche optique: effet de la sonde en deux dimensions
2004
This work consists in the development of a theoretical tool for the purpose to undertake numerical simulations able to take into account the coupling between the probe and the object. The first part, concerns the combination of the differential method and the algorithms T and S, to overcome numerical problems which appear in the cases where the size of system (probe - object) is more realistic. The developed global model is two-dimensional and applied in polarization TE under the normal diffraction condition. We have used the developed model to study the formation of optical image by monomodes and multimodes probes. The obtained optical images at constant height, have allowed us to study th…
Scanning electron microscopy of Antarctophthirus microchir (Phthiraptera: Anoplura: Echinophthiriidae): Studying morphological adaptations to aquatic…
2012
The members of the Family Echinophthiriidae (Phthiraptera: Anoplura) are unique among insects because they infest hosts with an amphibious lifestyle. During their evolution they developed morphological traits that are reflected in unique features. The SEM is a helpful tool to analyze them. Knowing in detail the external structure of these lice is the first step to understand the whole process that derived from the co-adaptation of lice and pinnipeds to the marine environment. For the first time, we studied the external structure of all stages of an echinophthiriid louse. The results are discussed in the light of their evolutionary, functional, and ecological implications. Fil: Leonardi, Mar…
Computer-Assisted Classification Patterns in Autoimmune Diagnostics: The AIDA Project.
2016
International audience; Antinuclear antibodies (ANAs) are significant biomarkers in the diagnosis of autoimmune diseases in humans, done by mean of Indirect ImmunoFluorescence (IIF) method, and performed by analyzing patterns and fluorescence intensity. This paper introduces the AIDA Project (autoimmunity: diagnosis assisted by computer) developed in the framework of an Italy-Tunisia cross-border cooperation and its preliminary results. A database of interpreted IIF images is being collected through the exchange of images and double reporting and a Gold Standard database, containing around 1000 double reported images, has been settled. The Gold Standard database is used for optimization of …
Un'autoetnografia per immagini
2020
Lo studio propone una riflessione geografica sulla fotografia (sui suoi usi e sui suoi sviluppi) in relazione a varie forme di spazialità. Attraverso l'analisi di alcune immagini sul Social Network Instagram viene presentata un'etnografia di tipo riflessivo utile a definire e discutere alcuni aspetti espistemologici della disciplina geografica, quali la metodologia da utilizzare, il posizionamento del ricercatore sul campo e i suoi oggetti di conoscenza e d'indagine scientifica. The study proposes a geographical reflection on photography (on its uses and its developments) in relation to various forms of spatiality. Through the analysis of some images on the Instagram Social Network, a refle…
Chapter 1 The Resolution Challenge in 3D Optical Microscopy
2009
Publisher Summary This chapter discusses the theoretical principles of 3D microscopy with the widespread realizations of 3D microscopy.Based on the paraxial diffraction equations, it has been shown that conventional microscopes, when dealing with 3D fluorescent samples, provide sets of 2D images. These images of the different transverse sections of the 3D object contain, in addition to the sharp image of the in focus section, the blurred images of the rest of the specimen. The paraxial formalism has been generalized in a very simple way to a non-paraxial context, showing that the equations that govern non-paraxial imaging are similar to those that govern paraxial imaging. The only differenc…
A Comparative Study on Feature Selection for Retinal Vessel Segmentation Using FABC
2009
This paper presents a comparative study on five feature selection heuristics applied to a retinal image database called DRIVE. Features are chosen from a feature vector (encoding local information, but as well information from structures and shapes available in the image) constructed for each pixel in the field of view (FOV) of the image. After selecting the most discriminatory features, an AdaBoost classifier is applied for training. The results of classifications are used to compare the effectiveness of the five feature selection methods.
Color difference threshold of chromostereopsis induced by flat display emission
2015
The study of chromostereopsis has gained attention in the backdrop of the use of computer displays in daily life. In this context, we analyze the illusory depth sense using planar color images presented on a computer screen. We determine the color difference threshold required to induce an illusory sense of depth psychometrically using a constant stimuli paradigm. Isoluminant stimuli are presented on a computer screen, which stimuli are aligned along the blue–red line in the computer display CIE xyY color space. Stereo disparity is generated by increasing the color difference between the central and surrounding areas of the stimuli with both areas consisting of random dots on a black backgr…
The use of very high resolution images for the estimation of Posidonia oceanica beach-cast morphology
2019
Posidonia oceanica is an endemic Mediterranean seagrass that forms wide and dense meadows from the surface to depths of about 40 m. During fall and winter, due to aging and storms, leaves and rhizomes break away from the seagrass meadows and accumulate on the shores (from a few centimeters in the water to several meters inshore) forming conspicuous beach-casts of P. oceanica detritus. These structures have received increasing attention in the last decade for the potential ecosystem services they provide in protecting the coast from erosion, linking marine and terrestrial food chains and contributing to carbon and nutrients fluxes. However, seagrass beach-cast morphology is not easy to estim…
Estimation of the volume of Posidonia oceanica detritus accumulations along Sicilian coasts by using very high resolution images
2019
Posidonia oceanica meadows are among the most important marine coastal ecosystems in the Mediterranean Sea due to several roles they are able to play. They, in fact, support high levels of primary production, enhance sedimentation of suspended particles through their canopies, prevent resuspension of marine sediments by means of roots and rhizomes and counteract coast erosion. Part of the primary production of this seagrass is not transferred to herbivores either immediately to detritus pathway but it can accumulate on the shore in form of banquette, typical structures exerting a significant role in protection of beaches from erosion. To accurately measure the extension, morphology, volume …