Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Giuseppe Longobardi.
Optical Engineering | 1996
Lois M. Hoffer; Franco Francini; Bruno Tiribilli; Giuseppe Longobardi
A fast system to reveal the presence and type of fabric defects during the weaving process is developed. Since the fabric is similar to a 2-D grid, its defects are clearly observed in the changes in its optical Fourier transform (OFT), which appears stationary while the fabric is moving across the loom. Previous work, based on the statistical parameters of the OFT, showed that the presence of faults can be detected when only global changes in the images are considered. We show that by selecting a small subset of pixels from the image as input to a neural network, fabric defects can not only be detected but also successfully identified. A knowledge-based system could conceivably be constructed to use this information to resolve problems with the loom in real time, without the need for operator intervention.
Optics and Lasers in Engineering | 1996
C. Castellini; Franco Francini; Giuseppe Longobardi; B. Tiribilli; Paola Sansoni
Fourier transformation and spatial filtering offer the possibility of detecting structural defects in a fabric. In this paper a method based on an optical Fourier transform technique during the weaving process is described. Significant variations in the Fourier pattern occurring in the presence of defective fabric are recognised with a CCD sensor joined to an electronic hardware system performing a simple algorithm.
Optical Engineering | 1996
Claudio Ciamberlini; Franco Francini; Giuseppe Longobardi; Paola Sansoni; Bruno Tiribilli
An optical method using Fourier transformation and spatial filtering is used to reveal defects in textured materials in real time. New optical structured filter types were developed including a self-adaptable mask made of photochromic polymers. The characteristics of these materials make possible very promising applications in pattern recognition such as that represented by a fabric.
Journal of Biomedical Optics | 1997
Claudio Ciamberlini; Vittorio Guarnieri; Giuseppe Longobardi; Pasquale Poggi; M. C. Donati; G. Panzardi
In order to evaluate the use of low level light (LLL) indocyanine green angiography in the diagnosis and treatment of central serous choroidopathy (CSC), a new system for LLL infrared videoangiography is described. The system was coupled with a standard fundus camera employing a low-power continuous light source. The system consists of a cooled charge-coupled device (CCD) camera and a third-generation image intensifier. The CCD camera investigates the pathologies of choroidal images with very good performance in terms of spatial resolution, dynamic range, and signal-to-noise ratio. The image intensifier carries out the choroidal angiography in real time. The results of 48 cases of CSC demonstrated the following ICGV features: focal RPE leakage; hyperfluorescent areas appearing in late phases and underlying the focal leakage or pigment epithelium detachment (PED); PED in the guise of early hyperfluorescent areas; delays in choroidal filling. The findings support the hypothesis that CSC originates in the choroid with localized hyperpermeability. The system described minimized retinal illumination and demonstrated increased angiographic resolution and contrast compared with conventional ICG angiographic systems.
Lasers, Optics, and Vision for Productivity in Manufacturing I | 1996
Claudio Ciamberlini; Franco Francini; Giuseppe Longobardi; Pasquale Poggi; Paola Sansoni; Bruno Tiribilli
An optical configuration for the detection of faults was developed and tested. The optical fourier transformation is the basic working principle of the system. When good fabric passes in front of the optical system the Fourier image, captured by the camera, shows well defined spots corresponding to the spatial frequencies of the tissue. If a defect occurs during production on the loom, the pattern changes significantly and a defect is easily detected in real time. A very simple electronic image processing based on thresholding and binary histograms allows to obtain very encouraging performance for its applicability to the looms. A compact device has been realized and tested in real working conditions on the loom.
Optics and Lasers in Engineering | 2001
Daniela Fontani; Franco Francini; Giuseppe Longobardi; Paola Sansoni
The paper describes a new sensor dedicated to measure and check the surface quality of mechanical products. The results were obtained comparing the light scattered from two different ranges of angles by means of 16 photodiodes. The device is designed for obtaining valid data from curved surfaces as that of a crankshaft. Experimental measurements show that the ratio between scattered and reflected light intensity increases with the surface roughness. This device was developed for the off-tolerance detection of mechanical pieces in industrial production. Results of surface quality on crankshaft supplied by Renault were carried out.
Optics and Lasers in Engineering | 1999
Daniela Fontani; Franco Francini; Giuseppe Longobardi; Paola Sansoni
Abstract Measurement of surface roughness on mechanical components, which may incorporate also critical profiles, using diffused light techniques is a very complex problem. This paper describes a new optoelectronic device employing a diode laser and an array of discrete photodetectors placed on an arc of circle and interfaced with a data acquisition board. The device allows an extended range of roughness measurements; it is compact, easy to be used and almost insensitive to external noise and vibrations. It provides an estimation of the surface quality parameters comparing the scattered light at two different ranges of angles thereby overcoming many of the earlier limitations. The experiment has evidenced that there is a good agreement between measurement results and theoretical model usually applicable to normally distributed surfaces.
Journal of Optics | 2002
Franco Francini; Giuseppe Longobardi; Paola Sansoni; Stefano Euzzor; Claudio Ciamberlini
A system to assess timber deformations has been developed using an array of optical distance sensors (ODS), each of which controls a strip of the timber determining how it deviates from flatness. The main characteristics of the ODS system are compactness, modularity and real-time elaboration software. The shape of the timber is reconstructed by sampling the distance between the timber and the ODS while the timber is running in the wood plant. The working principle of the ODS is based on the triangulation of a light spot. A low-power laser diode projects a light spot on the timber surface. The image of the spot moves on a position-sensitive detector (PSD) according to the distance between the optical system and the timber. Suitable software for computer-aided operation was developed at an industrial plant producing wood cutting systems. A prototype of the ODS system has been constructed and tested under real operating conditions.
Lasers in Ophthalmology III | 1996
Giuseppe Longobardi; Claudio Ciamberlini; Vittorio Guarnieri; G. Panzardi; M. C. Donati
ICG videoangiography has widely demonstrated its importance as an investigation method in several ocular pathologies. By means of an optoelectronic system developed by the authors, many cases of age related macular degeneration and central serous coroidopathy affecting patients of different ages have been investigated. The analysis of the eye fundus infrared-light images obtained allows the clinician to draw medical conclusions otherwise not obtainable with traditional visible-light techniques. A comprehensive survey and discussion of the most significant cases are presented.
International Symposium on Biomedical Optics Europe '94 | 1995
Giuseppe Longobardi; Claudio Ciamberlini; Vittorio Guarnieri; Pasquale Poggi; G. Panzardi; M. C. Donati; F. Faraldi
This paper describes the development of a double TV camera system incorporated in a standard fundus camera for imaging the choroidal vascular network with very low intensity infrared light. The equipment was employed to perform indocyanine green (ICG) choroidal angiography in several chorioretinal pathologies with particular interest in age related macular degeneration (AMD). An evaluation and comparison of fluorescein and ICG angiograms is carried out for the diagnosis, localization, and laser treatment evaluation of choroidal neovascularizations (CNV).