Search results for "ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION"
showing 10 items of 982 documents
The PolarLITIS Dataset: Road Scenes Under Fog
2022
Road scene analysis is a fundamental task for both autonomous vehicles and ADAS systems. Nowadays, one can find autonomous vehicles that are able to properly detect objects in the scene in good weather conditions; however, some improvements still need to be done when the visibility is altered. People claim that using some non-conventional sensors such as, infra-red or Lidar, combined with classical vision, enhances road scene analysis in optimal weather conditions. In this work, we present the improvements achieved using polarimetric imaging in the complex situation of some adverse weather conditions. This rich modality is known for its ability to describe an object not only by its intensit…
A robust aerial image registration method using Gaussian mixture models
2014
Aerial image registration is one of the bases in many aerospace applications, such as aerial reconnaissance and aerial mapping. In this paper, we propose a novel aerial image registration algorithm which is based on Gaussian mixture models. First of all, considering the characters of the aerial images, the work uses a shape feature detector which computes the boundaries of regions with nearly the same gray-value to extract invariant feature. Then, a Gaussian mixture models (GMM) based image registration model is built and solved to estimate the transformation matrix between two aerial images. Furthermore, the proposed method is applied on real aerial images, and the results demonstrate the …
Application prospects of silica core side-glowing optical fibers
2005
The side-emitting optical fibers are specially designed to stimulate leakage of the core-transmitted radiation via their side surfaces, so creating the effect of glowing tiny wires. The basic design concepts for this kind of optical fibers are discussed, as well as some of the present and potential future applications.
Quantitative colorimetric analysis of some inorganic salts using digital photography
2011
An analytical imaging approach to the quantitation of dissolved chemical species absorbed in the visible spectral region is reported. The approach uses digital images of a series of standard solutions of the target substance and their processing with appropriate software to assign a numeric value to each standard in terms of color intensity. Such a value is directly proportional to the analyte concentration and allows the construction of a calibration graph. The results thus obtained are compared with those provided by the classical spectrophotometricmethod used to run calibration curves for colored substances. The chemical imaging technique is relative simple and affordable; in fact, it ca…
A detailed method for creating digital 3D models of human crania: an example of close‑range photogrammetry based on the use of Structure‑from‑Motion …
2022
AbstractPhotogrammetry is a survey technique that allows for the building of three-dimensional (3D) models from digitized output data. In recent years, it has been confirmed as one of the best techniques to build 3D models widely used in several fields such as life and earth sciences, medicine, architecture, topography, archaeology, crime scene investigation, cinematography, and engineering. Close-range photogrammetry, in particular, has several applications in osteological studies allowing to create databases of 3D bone models available for subsequent qualitative and quantitative studies. This work provides a step-by-step guide of the photo acquisition protocol and the photogrammetric work…
Documenting carved stones from 3D models. Part II - Ambient occlusion to reveal carved parts.
2021
10 pages; International audience; Revealing carved parts in rock art is of primary importance and remains a major challenge for archaeological documentation. Computational geometry applied to 3D imaging provides a unique opportunity to document rock art. This study evaluates five algorithms and derivatives used to compute ambient occlusion and sky visibility on 3D models of Mongolian stelae, also known as deer stones. By contrast with the previous companion work, models are processed directly in 3D, without preliminary projection. Volumetric obscurance gives the best results for the identification of carved figures. The effects of model resolution and parameters specific to ambient occlusio…
Terrestrial laser scanning and close range photogrammetry for 3D archaeological documentation: the Upper Palaeolithic Cave of Parpalló as a case study
2010
Graphic and metric archaeological documentation is an activity that requires the capture of information from different sources, accurate processing and comprehensive analysis. If monitoring of the state of conservation is required, this task has to be performed before intervention, during and after the completion of the works in a repetitive way. This paper presents the use of terrestrial laser scanning (TLS) in order to effectively produce, prior to intervention, accurate and high-resolution 3D models of a cave with engravings dating back to the Upper Palaeolithic era. The processing of the TLS data is discussed in detail in order to create digital surface models. The complexity of the cav…
Energy savings for indoor lighting in a shopping mall: A case of study
2018
The paper presents an application of energy saving in the final users. In particular, the case of study evaluates the energy consumptions of a big shopping mall, located in the middle part of Italy, illuminated by fluorescent lamps. In order to reduce the energy demand, the case of study shows a first solution based on LED lamps; a second step considers the adding of a building automation system, maximizing the energy saving, thanks lighting sensors that module the luminous flux taking in count of natural lighting through skylights.
Intraocular Telescopic System Design: Optical and Visual Simulation in a Human Eye Model
2016
Purpose. To design an intraocular telescopic system (ITS) for magnifying retinal image and to simulate its optical and visual performance after implantation in a human eye model. Methods. Design and simulation were carried out with a ray-tracing and optical design software. Two different ITS were designed, and their visual performance was simulated using the Liou-Brennan eye model. The difference between the ITS was their lenses’ placement in the eye model and their powers. Ray tracing in both centered and decentered situations was carried out for both ITS while visual Strehl ratio (VSOTF) was computed using custom-made MATLAB code. Results. The results show that between 0.4 and 0.8 mm of d…
Fuzzy C-Means Segmentation on Brain MR Slices Corrupted by RF-Inhomogeneity
2007
Brain MR Images corrupted by RF-Inhomogeneity exhibit brightness variations in such a way that a standard Fuzzy C-Means (fcm) segmentation algorithm fails. As a consequence, modified versions of the algorithm can be found in literature, which take into account the artifact. In this work we show that the application of a suitable pre-processing algorithm, already presented by the authors, followed by a standard fcm segmentation achieves good results also. The experimental results ones are compared with those obtained using SPM5, which can be considered the state of the art algorithm oriented to brain segmentation and bias removal.