Search results for "ndc"
showing 10 items of 1025 documents
Spatially-multiplexed interferometric microscopy (SMIM): converting a standard microscope into a holographic one
2014
We report on an extremely simple, low cost and highly stable way to convert a standard microscope into a holographic one. The proposed architecture is based on a common-path interferometric layout where the input plane is spatially-multiplexed to allow reference beam transmission in a common light-path with the imaging branch. As consequence, the field of view provided by the layout is reduced. The use of coherent illumination (instead of the broadband one included in the microscope) and a properly placed one-dimensional diffraction grating (needed for the holographic recording) complete the experimental layout. The proposed update is experimentally validated in a regular Olympus BX-60 upri…
Vector anisotropic filter for multispectral image denoising
2015
In this paper, we propose an approach to extend the application of anisotropic Gaussian filtering for multi- spectral image denoising. We study the case of images corrupted with additive Gaussian noise and use sparse matrix transform for noise covariance matrix estimation. Specifically we show that if an image has a low local variability, we can make the assumption that in the noisy image, the local variability originates from the noise variance only. We apply the proposed approach for the denoising of multispectral images corrupted by noise and compare the proposed method with some existing methods. Results demonstrate an improvement in the denoising performance.
Attitude estimation from polarimetric cameras
2018
International audience; In the robotic field, navigation and path planning applications benefit from a wide range of visual systems (e.g. perspective cameras, depth cameras, catadioptric cameras, etc.). In outdoor conditions, these systems capture information in which sky regions cover a major segment of the images acquired. However, sky regions are discarded and are not considered as visual cue in vision applications. In this paper, we propose to estimate attitude of Unmanned Aerial Vehicle (UAV) from sky information using a polarimetric camera. Theoretically , we provide a framework estimating the attitude from the skylight polarized patterns. We showcase this formulation on both simulate…
El aula como caja de resonancia para la creación sonora: nuevas arquitecturas y herramientas tecnológicas para acercar el arte sonoro al ámbito educa…
2019
RESUMEN: Este artículo reflexiona sobre la importancia de repensar los espacios que habitamos de acuerdo con la idea de que el mundo físico y el digital interactúen de manera natural. A partir de esta premisa, y en el ámbito educativo-musical, las prácticas desarrolladas en el MusicLAB CR-209 del IES Arabista Ribera de Carcaixent (Valencia) son una muestra de cómo estas nuevas arquitecturas pueden favorecer el desarrollo de la creatividad. Acorde con las posibilidades que ofrece la tecnología actual, esta aula laboratorio está concebido como un espacio para la experimentación y la improvisación. El objeto de este artículo es describir ?La Máquina Interestelar?, una propuesta pedagógica inte…
Pitfalls on Postmortem Imaging: The Need of Blending Conventional and Virtual Autopsy on Burnt-Charred Body
2019
Joining forensic traditional autopsy and CT-MR postmortem virtual approach may assist forensic experts in adequate reconstruction of cause, manner, and way of death, significantly to find evidence of found wound/fracture and relative interpretation. Evaluation of criminal burning is often a difficult challenge in the view of misinterpretation of wound/fracture victims and usually poor case history of this criminal offense. In this scenario, a strong collaboration between imaging and classical forensic techniques is helpful.
Automatic Extraction of Blood Vessels, Bifurcations and End Points in the Retinal Vascular Tree
2008
In this paper we present an effective algorithm for automated extraction of the vascular tree in retinal images, including bifurcations, crossovers and end-points detection. Correct identification of these features in the ocular fundus helps the diagnosis of important systematic diseases, such as diabetes and hypertension. The pre-processing consists in artefacts removal based on anisotropic diffusion filter. Then a matched filter is applied to enhance blood vessels. The filter uses a full adaptive kernel because each vessel has a proper orientation and thickness. The kernel of the filter needs to be rotated for all possible directions. As a consequence, a suitable kernel has been designed …
‘I shared the joy’: sport-related social support and communality on Instagram
2020
The popularity of sharing photographs on digital platforms has increased significantly due to the communicative affordances of mobile media and the emergence of photo-sharing applications, such as Instagram. In this paper, we examine how social support and communality can be built and reinforced through digital visual communication. We focus especially on photo sharing in the context of recreational climbing and trail running. In a qualitative study with Finnish climbers and runners, we asked what meanings sports practitioners ascribe to the practice of sharing and observed how they communicate these meanings through photographs. The results indicate that different types of visual content b…
A WAVELET OPERATOR ON THE INTERVAL IN SOLVING MAXWELL'S EQUATIONS
2011
In this paper, a differential wavelet-based operator defined on an interval is presented and used in evaluating the electromagnetic field described by Maxwell's curl equations, in time domain. The wavelet operator has been generated by using Daubechies wavelets with boundary functions. A spatial differential scheme has been performed and it has been applied in studying electromagnetic phenomena in a lossless medium. The proposed approach has been successfully tested on a bounded axial-symmetric cylindrical domain.
A Portable Dynamic Laser Speckle System for Sensing Long-Term Changes Caused by Treatments in Painting Conservation
2018
[EN] Dynamic laser speckle (DLS) is used as a reliable sensor of activity for all types of materials. Traditional applications are based on high-rate captures (usually greater than 10 frames-per-second, fps). Even for drying processes in conservation treatments, where there is a high level of activity in the first moments after the application and slower activity after some minutes or hours, the process is based on the acquisition of images at a time rate that is the same in moments of high and low activity. In this work, we present an alternative approach to track the drying process of protective layers and other painting conservation processes that take a long time to reduce their levels …
FABC: Retinal Vessel Segmentation Using AdaBoost
2010
This paper presents a method for automated vessel segmentation in retinal images. For each pixel in the field of view of the image, a 41-D feature vector is constructed, encoding information on the local intensity structure, spatial properties, and geometry at multiple scales. An AdaBoost classifier is trained on 789 914 gold standard examples of vessel and nonvessel pixels, then used for classifying previously unseen images. The algorithm was tested on the public digital retinal images for vessel extraction (DRIVE) set, frequently used in the literature and consisting of 40 manually labeled images with gold standard. Results were compared experimentally with those of eight algorithms as we…