Search results for "Image Analysi"

On the measurement of bubble size distribution in gas–liquid contactors via light sheet and image analysis

2010

Abstract Particle image velocimetry techniques coupled with advanced image processing tools are receiving an increasing interest for measuring flow quantities and local bubble-size distributions in gas–liquid mechanically agitated vessels. When trying to analyze image information the problem arises that bubble sizes are generally underestimated, due to the fact that the laser sheet used for lighting the system randomly cuts bubbles over non-diametrical planes, leading to an apparent bubble size distribution even in the ideal case of single sized bubbles. Clearly in the case of bubbles with a size distribution the experimental information obtained is affected by the superposition of effects.…

Metodi automatici di analisi e caratterizzazione di esami radiologici del massiccio facciale.

L'obiettivo di questo lavoro è lo sviluppo di algoritmi e procedure di analisi di referti radiografici digitali di tipo CBCT delle strutture della mandibola e dell’apparato dentario. In particolare, mediante un’opportuna campagna di sperimentazione, in collaborazione con i reparti di radiologia ed odontoiatria del Policlinico di Palermo, è stata realizzata un procedura in grado di: • eliminare i problemi di sovrapponibilità dei referti tridimensionali effettuati in tempi successivi; • identificare lo spazio parodontale su indagini CBCT per la valutazione dei possibili difetti nello stesso e prevedere l’insorgenza di parodontiti. • individuare gli elementi di maggiore interesse medico caratt…

Approche multi-critère pour la caractérisation des adventices

2022

The objective of this thesis is to develop a way to detect weeds in a field using multispectral images, in order to determine which weeds should be eliminated during the current crop cycle and more particularly at the early stages. The multi-criteria approach focuses on the spatial arrangement, the spec- tral signature, the morphology and the tex- ture of the plants located in the plots. This work proposes a method for selecting the best criteria for optimal discrimination for a given setup. Prior to the extraction of these crite- ria, a set of methods was developed in order to correct the errors of the acquisition de- vice, to precisely detect the vegetation and then to identify within the…

Surgical management of pleomorphic adenoma of parotid gland in elderly patients: Role of morphological features

2014

AbstractThe neoplasms of the salivary glands account for 2% of head and neck tumors and the most common form is the Pleomorphic adenoma (PA). Parotid gland is affected from 80% to 90% of cases. In elderly these tumors occur mostly in females. These benign tumors are composed of epithelial and myoepithelial cells that are arranged with various morphological patterns and subtypes. The classification of these tumors is also based on the amount and nature of the stroma. In literature there is an almost complete consensus that, in the major salivary glands, PAs are enclosed by a layer of fibrous tissue often called “capsule” but there is disagreement about the form, extension and thickness of th…

B-Scan image analysis for position and shape defect definition in plates

2016

Definition of size, shape and location of defects into a mechanical component is of extreme importance in the manufacturing industry in general and particularly in high-tech applications, and in applications that can become dangerous due to the structural failure of mechanical components. In this paper, a laser-UT system has been used to define position and shape of internal defects in aluminum plates. An infrared pulsed laser is used to generate ultrasonic waves in a point of the plate and a CW laser interferometer is used as receiver to acquire the out-of-plane displacements due to the ultrasonic waves in another point of the plate. The method consists of acquiring a B-Scan map on which s…

Long slide holders for microscope stages

2018

ABSTRACT The use of automated techniques for image analysis of microscopic wood specimens together with new procedures for the preparation of stained xylem tissue support the use of quantitative wood anatomy. These techniques and procedures are especially useful in the studies of retrospective analysis of xylem phenology, reaction(s) of trees to stressful conditions of growth, or reconstruction of long-term growth trends. The unresolved technical problems during the digitalization of cross sections from entire increment cores were stabilization and precise shifting of long microscopic specimens onto the optical microscope stage. For this reason, we have developed a long slide holder for mic…

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.

Nonlinear Disorder Mapping Through Three-Wave Mixing

2010

We implement a simple and powerful approach to characterize the domain distribution in the bulk of quadratic ferroelectric crystals via far-field second-harmonic spectroscopy. The approach is demonstrated in a lithium tantalate sample with periodic electric field poling and random mark-to-space ratio.

A Medium Level Language for Pyramid Architectures

1989

In the paper a Parallel C Languages for pyramid architectures is described. The concept of context is introduced in order to handle concurrence between processes in massive parallel machines. Feature implementation on the PAPIA-machine are given.

Reaction-Diffusion Network For Geometric Multiscale High Speed Image Processing

2010

International audience; In the framework of heavy mid-level processing for high speed imaging, a nonlinear bi-dimensional network is proposed, allowing the implementation of active curve algorithms. Usually this efficient type of algorithm is prohibitive for real-time image processing due to its calculus charge and the inadequate structure for the use of serial or parallel architectures. Another kind of implementation philosophy is proposed here, by considering the active curve generated by a propagation phenomenon inspired from biological modeling. A programmable nonlinear reaction-diffusion system is proposed under front control and technological constraints. Geometric multiscale processin…