Search results for "image analysis."

An automated procedure for computing the packing properties of dense and locked sands by image analysis of thin sections

2014

The macroscopic mechanical behaviour of dense sands originates to a great extent from their microstructural characteristics such as the coordination number, the grain contact and the packing density indexes. The study of intergranular contacts and the reckoning of these indexes may be carried out on planar images of the grains either by means of time-consuming visual inspection assisted by CAD or by automatic image analysis. An innovative method for the automatic determination of microstructural characteristics of sands based on image analysis of thin section is proposed. Tests performed on a locked sand show that the proposed method is much more effective, convenient and faster than the us…

CFD prediction of bubble behavior in two-dimensional gas-solid fluidized beds

2009

This work focuses on the computational fluid dynamics (CFD) simulation of a laboratory-scale, two-dimensional fluidized bed and the relevant experiments in order to validate the prediction capability of the adopted codes and models. Both experimental and computational quantitative data were analyzed by means of an original digital image analysis technique, allowing for coherent comparison of computational and experimental results. In particular, this work analyzes the capability of the CFD simulations in predicting the fluctuating behavior of bubbling fluidized beds by means of frequency analysis of bubble-related phenomena.

Automated segmentation and description of the internal morphology of human permanent teeth by means of micro-CT

2020

High-resolution micro-computed tomography is a powerful tool to analyze and visualize the internal morphology of human permanent teeth. It is increasingly used for investigation of epidemiological questions to provide the dentist with the necessary information required for successful endodontic treatment. The aim of the present paper was to propose an image processing method to automate parts of the work needed to fully describe the internal morphology of human permanent teeth. One hundred and four human teeth were scanned on a high-resolution micro-CT scanner using an automatic specimen changer. Python code in a Jupyter notebook was used to verify and process the scans, prepare the dataset…

Medical Imaging Applications: Three Case Studies

2006

Reliable Detection and Smart Deletion of Malassez Counting Chamber Grid in Microscopic White Light Images for Microbiological Applications

2015

AbstractIn biology, hemocytometers such as Malassez slides are widely used and are effective tools for counting cells manually. In a previous work, a robust algorithm was developed for grid extraction in Malassez slide images. This algorithm was evaluated on a set of 135 images and grids were accurately detected in most cases, but there remained failures for the most difficult images. In this work, we present an optimization of this algorithm that allows for 100% grid detection and a 25% improvement in grid positioning accuracy. These improvements make the algorithm fully reliable for grid detection. This optimization also allows complete erasing of the grid without altering the cells, whic…

Automatic Assessment of Depression Based on Visual Cues: A Systematic Review

2019

International audience; Automatic depression assessment based on visual cues is a rapidly growing research domain. The present exhaustive review of existing approaches as reported in over sixty publications during the last ten years focuses on image processing and machine learning algorithms. Visual manifestations of depression, various procedures used for data collection, and existing datasets are summarized. The review outlines methods and algorithms for visual feature extraction, dimensionality reduction, decision methods for classification and regression approaches, as well as different fusion strategies. A quantitative meta-analysis of reported results, relying on performance metrics r…

Toward an Integrated System for Surveillance and Behaviour Analysis of Groups and People

2013

Security and INTelligence SYStem is an Italian research project which aims to create an integrated system for the analysis of multi-modal data sources (text, images, video, audio), to assist operators in homeland security applications. Within this project the Scientific Research Unit of the University of Palermo is responsible of the image and video analysis activity. The SRU of Palermo developed a web service based architecture that provides image and video analysis capabilities to the integrated analysis system. The developed architecture uses both state of the art techniques, adapted to cope with the particular problem at hand, and new algorithms to provide the following services: image …

A Novel Technique for Monitoring the W-Beam Guardrails

2014

The paper addresses the problem of the measurement of guardrails’ deformations by means automatic analysis of optical images. The technique is founded on the analysis of high-resolution photos, obtained by means of 3D camera installed into a data vehicle. The novel methodology has been used to calculate the longitudinal safety barrier deformations for one W-beam guardrails installed along a rural road in Italy. The procedure has shown that digital image analysis can be used with the aim to monitoring guardrails and, therefore, for guarantee reasonable levels of protection against serious ran-off-road crashes.

Automated Detection of Optic Disc Location in Retinal Images

2008

This contribution presents an automated method to locate the optic disc in color fundus images. The method uses texture descriptors and a regression based method in order to determine the best circle that fits the optic disc. The best circle is chosen from a set of circles determined with an innovative method, not using the Hough transform as past approaches. An evaluation of the proposed method has been done using a database of 40 images. On this data set, our method achieved 95% success rate for the localization of the optic disc and 70% success rate for the identification of the optic disc contour (as a circle).

Two-dimensional apparent microfabric of the basal Late Weichselian till and associated shear zone: case study from western Latvia

2008

The examination of glacial sediments in thin sections has become a common procedure in recent years. Apparent sand grain orientation (microfabric) in thin sections is one of the key elements marking certain microstructures. In an attempt to make till micromorphology studies less subjective and investigate the orientation of sand-sized particles in tills, we have developed an image analysis procedure to measure and analyse the spatial distribution of the till microfabric. We studied 13 thin sections of the Weichselian subglacial till and basal shear zone outcropping in the Baltic Sea bluffs at the Ziemupe site in western Latvia. The results were visualized as a two-dimensional grid of rose d…