Search results for "image analysis."
showing 10 items of 144 documents
UNE APPROCHE PARALLELE D'EVALUATION DES PARAMETRES DE TEXTURE POUR L'ANALYSE D'IMAGES DE GRANDE TAILLE
2011
International audience; The main objective of this paper is to develop a new image processing technique that could better be adapted to the processing of large and complex images, especially SAR images, in relation to the former methods of our works. We propose here a new approach of textural parameters evaluation which is about (Ng+1)n-1 times faster than the co-occurrence matrix approach considered as classical, where n is the order of the textural parameter and Ng being the maximum grey level in the image. This approach is based on a new modeling of textural parameters of a generic order n>1 equivalent to the classical formulation, but which is no longer based on frequency matrix (co-occ…
Image classification based on 2D feature motifs
2013
The classification of raw data often involves the problem of selecting the appropriate set of features to represent the input data. In general, various features can be extracted from the input dataset, but only some of them are actually relevant for the classification process. Since relevant features are often unknown in real-world problems, many candidate features are usually introduced. This degrades both the speed and the predictive accuracy of the classifier due to the presence of redundancy in the candidate feature set. In this paper, we study the capability of a special class of motifs previously introduced in the literature, i.e. 2D irredundant motifs, when they are exploited as feat…
Effects of pyrolysis temperature on the hydrologically relevant porosity of willow biochar
2018
Biochar pore space consists of porosity of multiple length scales. In direct water holding applications like water storage for plant water uptake, the main interest is in micrometre-range porosity since these pores are able to store water that is easily available for plants. Gas adsorption measurements which are commonly used to characterize the physical pore structure of biochars are not able to quantify this pore-size range. While pyrogenetic porosity (i.e. pores formed during pyrolysis process) tends to increase with elevated process temperature, it is uncertain whether this change affects the pore space capable to store plant available water. In this study, we characterized biochar poro…
Development of Bioimage Analysis tools for the study of neurogenesis and neurodegeneration
2021
ANTECEDENTES La combinación sinérgica de métodos automatizados de captura y análisis de bioimagen está emergiendo como un enfoque de vanguardia para abordar muchas cuestiones biológicas. Sin embargo, hay muchos campos en los que estas técnicas aún no se implementan y, en cambio, todavía se basan en la inspección visual y el análisis manual, que inevitablemente limitan el rendimiento alcanzable y son más propensos a introducir el sesgo del investigador. Por lo tanto, aún queda un gran esfuerzo por hacer en la difusión del uso de tecnologías de bioimagen de vanguardia en los campos de las ciencias de la vida con una gran dependencia de métodos de microscopía. En la presente tesis, nuestro obj…
Anatomical and functional macular changes after rhegmatogenous retinal detachment with macula off
2011
International audience; Purpose: To evaluate the correlation between morphologic changes in the outer retina and visual function after successful repair of rhegmatogenous retinal detachment with macula off. Methods: Thirty patients (30 eyes) with successful repair of rhegmatogenous retinal detachment (RD) after macula off and a minimum 6-month follow-up after the surgery were examined. Preoperative characteristics of the RD (visual acuity and duration) were collected. Postoperative visual acuity measurement with ETDRS scale and fundus autofluorescence (FAF) were performed. Spectral-Domain Optical Coherence Tomography (HRA OCT) of outer retina was performed to analyse the number of disrupted…
Developing and comparing methods for mapping habitat types and conservation values using remote sensing data and GIS methods
2014
Analysis of microtomographic images of porous heterogeneous materials
2015
In this work, we study the phases of image processing chain of microtomographic imag- ing in order to obtain reliable results while optimizing the time spent on denoising and segmentation. We consider that the decisions made at the early phases of the processing chain are most important and the selection made there essentially determine the overall quality of imaging process. We also compare here various denoising method qualita- tively, however, we think that the pure noise removal ability is not the only requirement for noise removal in microtomographic images. By proper denoising we can affect selec- tion of segmentation methods and, thus, also the quality of the analysis. Additionally, …
Single-cell analysis of population context advances RNAi screening at multiple levels
2012
Isogenic cells in culture show strong variability, which arises from dynamic adaptations to the microenvironment of individual cells. Here we study the influence of the cell population context, which determines a single cell's microenvironment, in image‐based RNAi screens. We developed a comprehensive computational approach that employs Bayesian and multivariate methods at the single‐cell level. We applied these methods to 45 RNA interference screens of various sizes, including 7 druggable genome and 2 genome‐wide screens, analysing 17 different mammalian virus infections and four related cell physiological processes. Analysing cell‐based screens at this depth reveals widespread RNAi‐induce…
Visual Contrast Modulates Operant Learning Responses in Larval Zebrafish.
2018
The larval zebrafish is a promising vertebrate model organism to study neural mechanisms underlying learning and memory due to its small brain and rich behavioral repertoire. Here, we report on a high-throughput operant conditioning system for zebrafish larvae, which can simultaneously train 12 fish to associate a visual conditioned pattern with electroshocks. We find that the learning responses can be enhanced by the visual contrast, not the spatial features of the conditioned patterns, highlighted by several behavioral metrics. By further characterizing the learning curves as well as memory extinction, we demonstrate that the percentage of learners and the memory length increase as the co…