Search results for "methodologies"
showing 10 items of 2106 documents
Aperiodic Diffract: Study of diffraction gratings
2014
In this work we introduce a virtual laboratory, APERIODIC DIFFRACT, developed in Matlab GUI (Graphical User Interface) as an informatics tool for teaching the diffractive properties of aperiodic gratings. This GUI allows the student to generate aperiodic sequences by iterating and lets to study the spectra for different iterating orders.<br /><br />
Super-resolved Imaging based upon spatial depolarization of light
2010
In this paper we present a new approach allowing the surpassing of the diffraction based limitation for the achievable resolution provided by imaging systems. It is based on an encoding-decoding process of various spatial pixels or regions in the field of view of the imaged object by orthogonal and differently time varying polarization states. The reconstruction of the original spatial information is obtained by applying a decoding process in a way similar to the encoding one. Although all the spatial information is summed and mixed together by the system, the decoding provides super resolved imaging since in every spatial position the undesired spatial information having time varying polar…
Super-resolved imaging with randomly distributed, time- and size-varied particles
2009
In this paper we present a super-resolved approach aimed at overcoming the diffraction limit in imaging systems. It is based on place randomly and time-varied particles having different sizes on the top of the sample. By considering particle sizes smaller than the object's minimum detail that an imaging system can resolve, it is possible to recover a high resolution image from a set of low resolution images while before capturing each image we produce a randomly modified distribution of the particles by vibrating the sample. The simulation process as well as experimental results validates the proposed approach that includes effectively decreasing the F number of the imaging system while bei…
Geometrical super resolved lensless imaging
2011
In the field of super resolution researchers are trying to overcome both the diffraction as well as the geometrical bounds of an imaging system. In this paper we present a recently developed approach that aims to overcome the geometrical bounds while using a unified spatial light modulator (SLM) based lensless configuration.
Super-resolved or field of view enlarged imaging based upon spatial depolarization of light
2010
Abstract In this paper we present a new approach allowing the surpassing of the diffraction based limitation for the achievable resolution provided by imaging systems. It is based on an encoding–decoding process of various spatial pixels or regions in the field of view of the imaged object by orthogonal and differently time varying polarization states. The reconstruction of the original spatial information is obtained by applying a decoding process in a way similar to the encoding one. Although all the spatial information is summed and mixed together by the system, the decoding provides super-resolved imaging since in every spatial position the undesired spatial information having time vary…
Transverse resolution improvement using rotating-grating time-multiplexing approach
2008
The ability to improve the limited resolving power of optical imaging systems while approaching the theoretical diffraction limit has been an attractive discipline with growing interest over the last years due to its benefits in many applied optics systems. This paper presents a new approach to achieve transverse superresolution in far-field imaging systems, with direct application in both digital microscopy and digital holographic microscopy. Theoretical analysis and computer simulations show the validity of the presented approach.
Detection of H. pylori induced gastric inflammation by diffuse reflectance analysis
2018
International audience; Spectral acquisitions contain rich information and thus, are promising modalities for early detection of gastric diseases. In this study, we analyze the diffuse reflectance of the gastric inflammatory lesions induced by the bacterium H. pylori in the mouse stomach. A pipeline has been designed to characterize and classify spectra acquired on mice. The pipeline is based on a band clustering algorithm followed by the computation of meaningful division and subtraction features and by classification with a linear SVM classifier. Currently, the pipeline is able to recognize inflamed stomachs spectra with an accuracy of 98%. These results are promising and the same pipelin…
Object tracking in medical imaging using a 2D active mesh system
2003
International audience; Abstract: This article proposes a technique for tracking moving organs in medical imaging. It can be split into two stages. We first initialize a 2D-triangular mesh on the first image of the sequence. We distinguish different objects of interest by grouping together the triangles that make them up. Afterwards, we deform this mesh on the successive images in order to track each identified object. The tracking stage uses optical flow by adding a node relaxation step to avoid mesh deteriorations. The mesh deformations analysis provides access to motion information along the sequence. This technique is applied to a cine-MRI sequences of the heart and allows the analysis …
Depth Map Generation by Image Classification
2004
This paper presents a novel and fully automatic technique to estimate depth information from a single input image. The proposed method is based on a new image classification technique able to classify digital images (also in Bayer pattern format) as indoor, outdoor with geometric elements or outdoor without geometric elements. Using the information collected in the classification step a suitable depth map is estimated. The proposed technique is fully unsupervised and is able to generate depth map from a single view of the scene, requiring low computational resources.
An Enhanced Detector of Blurred and Noisy Edges
2007
Detecting edges in digital images is a tricky operation in image processing since images may contain areas with different degrees of noise, blurring and sharpness. Such operation represents an important step of the whole process of similarity shape analysis and retrieval.