Search results for "image"
showing 10 items of 6818 documents
Euclid preparation : XIII. Forecasts for galaxy morphology with the Euclid Survey using deep generative models
2022
We present a machine learning framework to simulate realistic galaxies for the Euclid Survey, producing more complex and realistic galaxies than the analytical simulations currently used in Euclid. The proposed method combines a control on galaxy shape parameters offered by analytic models with realistic surface brightness distributions learned from real Hubble Space Telescope observations by deep generative models. We simulate a galaxy field of 0.4 deg2 as it will be seen by the Euclid visible imager VIS, and we show that galaxy structural parameters are recovered to an accuracy similar to that for pure analytic Sérsic profiles. Based on these simulations, we estimate that the Euclid Wide …
A fully automatic method for biological target volume segmentation of brain metastases
2016
Leksell Gamma Knife is a mini-invasive technique to obtain a complete destruction of cerebral lesions delivering a single high dose radiation beam. Positron Emission Tomography (PET) imaging is increasingly utilized for radiation treatment planning. Nevertheless, lesion volume delineation in PET datasets is challenging because of the low spatial resolution and high noise level of PET images. Nowadays, the biological target volume (BTV) is manually contoured on PET studies. This procedure is time expensive and operator-dependent. In this article, a fully automatic algorithm for the BTV delineation based on random walks (RW) on graphs is proposed. The results are compared with the outcomes of…
Dijon, ville d'art et capitale de la gastronomie. L'invention d'une image urbaine (1919-1935)
2014
International audience; Maire de Dijon de 1919 à 1935, Gaston-Gérard marque profondément la scène municipale locale. Dans une politique qui vise à dynamiser le développement de la ville, le maire de Dijon se distingue, de bien de ses pairs, par la place essentielle qu'il accorde à l'intervention de la ville dans les domaines culturels. Le discours met en scène trois registres complémentaires qui fondent la légitimité de cette action : le rayonnement de la ville ; le renouveau régionaliste et la démocratisation des arts. La création de la Foire gastronomique, en 1921, participe de cette nouvelle image urbaine : « Dijon, ville d’art et capitale de la gastronomie ».
An exploratory study of gazing behavior during live performance
2009
It is known that the visual information given by performers during a performance works as a useful channel of communication to the audience. In my previous studies, many performers referred to the importance of gazing behavior or eye contact. The purpose of this research is to explore the role of gaze during live performance by measuring the timing and direction of gazing. The hypotheses are as follows: [1] Gazing behavior depends on the musical structure. [2] Gazing behavior is used for the communication between performers which is necessary during performance. [3] Performers set their gazing direction in order to contribute to the audience’s understanding of the music. This research was e…
AUTOMATIC RETINA EXUDATES SEGMENTATION WITHOUT A MANUALLY LABELLED TRAINING SET
2011
International audience; Diabetic macular edema (DME) is a common vision threatening complication of diabetic retinopathy. In a large scale screening environment DME can be assessed by detecting exudates (a type of bright lesions) in fundus images. In this work, two new methods for the detection of exudates are presented. The methods do not require a lesion training set so the need to ground-truth data is avoided with significant time savings and independence from human error. We evaluate our algorithm with a new publicly available dataset from various ethnic groups and levels of DME. Also, we compare our results with two recent exudate segmentation algorithms on the same dataset. In all of …
Schematic eye models to mimic the behavior of the accommodating human eye
2018
A simplified version of the human eye is known as schematic eye model. Since the first attempts in the middle of the 19th century, numerous approaches describing new schematic eye models have been introduced. Some of them are able to describe the accommodation ability of the human eye. Accommodative schematic eyes could be of great interest since they are able to explain the functionality of the human eye and they can be easily used for different research purposes. Some of these include the design and testing of multifocal ophthalmic solutions, evaluation of the effect of optical aberrations on the retinal image quality, and study of the optical performance of the eye at different distances…
Classifying DME vs Normal SD-OCT volumes: A review
2016
International audience; This article reviews the current state of automatic classification methodologies to identify Diabetic Macular Edema (DME) versus normal subjects based on Spectral Domain OCT (SD-OCT) data. Addressing this classification problem has valuable interest since early detection and treatment of DME play a major role to prevent eye adverse effects such as blindness. The main contribution of this article is to cover the lack of a public dataset and benchmark suited for classifying DME and normal SD-OCT volumes, providing our own implementation of the most relevant methodologies in the literature. Subsequently, 6 different methods were implemented and evaluated using this comm…
When virtual and real worlds coexist: Visualization and visual system affect spatial performance in augmented reality
2021
New visualization approaches are being actively developed aiming to mitigate the effect of vergence-accommodation conflict in stereoscopic augmented reality; however, high interindividual variability in spatial performance makes it difficult to predict user gain. To address this issue, we investigated the effects of consistent and inconsistent binocular and focus cues on perceptual matching in the stereoscopic environment of augmented reality using a head-mounted display that was driven in multifocal and single focal plane modes. Participants matched the distance of a real object with images projected at three viewing distances, concordant with the display focal planes when driven in the mu…
Classification of SD-OCT Volumes with LBP: Application to DME Detection
2015
International audience; This paper addresses the problem of automatic classification of Spectral Domain OCT (SD-OCT) data for automatic identification of patients with Diabetic Macular Edema (DME) versus normal subjects. Our method is based on Local Binary Patterns (LBP) features to describe the texture of Optical Coherence Tomography (OCT) images and we compare different LBP features extraction approaches to compute a single signature for the whole OCT volume. Experimental results with two datasets of respectively 32 and 30 OCT volumes show that regardless of using low or high level representations, features derived from LBP texture have highly discriminative power. Moreover, the experimen…
Classification of SD-OCT Volumes Using Local Binary Patterns: Experimental Validation for DME Detection
2016
International audience; This paper addresses the problem of automatic classification of Spectral Domain OCT (SD-OCT) data for automatic identification of patients with Diabetic Macular Edema (DME) versus normal subjects. Optical Coherence Tomography (OCT) has been a valuable diagnostic tool for DME, which is among the most common causes of irreversible vision loss in individuals with diabetes. Here, a classification framework with five distinctive steps is proposed and we present an extensive study of each step. Our method considers combination of various pre-processings in conjunction with Local Binary Patterns (LBP) features and different mapping strategies. Using linear and non-linear cl…