Search results for "Digital CA"
showing 10 items of 29 documents
Digital video-electrochemistry (DVEC) to assess electrochromic materials in the frequency domain: RGB colorimetry impedance spectroscopy
2021
Abstract This work is the first one allowing the characterization of electrochromic devices simultaneously at various parts on their surface and different rates of color change. We describe a new proficient and affordable methodology for reporting electrochromic parameters such as coloration efficiency, optical contrast, and switching time based on the use of digital video-electrochemistry (DVEC) in the ac regime, namely RGB colorimetry impedance spectroscopy. Simultaneously with the electrochemical impedance spectroscopy, the RGB color changes of an electrochromic electrode were recorded by a CCD digital camera at 120 digital images per second. In such conditions, RGB electrochromic change…
Dalla participatory culture all’utente riproduttivo. Partecipazione, informazione e valore nei processi di produzione capitalistica del Web (Prima pa…
2015
Il presente contributo costituisce la prima parte di un articolo più esteso che verrà pubblicato integralmente nei prossimi numeri di “EmergingSeries Journal”. In questa prima sezione, a partire da una breve panoramica sulle principali direzioni che orientano i cambiamenti dei grandi player del Web, si tenterà di avviare una riflessione sul ruolo dell‟utente partecipativo all‟interno dei processi di produzione capitalistica che animano le piattaforme online. In questa sede, ripercorrendo i tratti essenziali del consumo partecipativo così come definiti nell‟ambito della participatory culture, se ne metteranno in evidenza alcuni tratti problematici e si sosterrà che l‟analisi del rapporto tra…
Configurable Passband Imaging Spectrometer Based on Acousto-optic Tunable Filter
2008
This work presents a new configurable imaging spectrometer called Autonomous Tunable Filtering System (ATFS). The system can be configured to acquire a single narrow spectral band, a composite multispectral image, or a broad pass-band. This flexibility is given by the use of an Acousto-Optic Tunable Filter (AOTF) driven by a programmable radio frequency (rf) signal generator. The AOTF acts as a light-diffraction element which output wavelength is selected by the frequency of an rf signal applied to it. The designed rf driver is based on a high-speed Digital-to-Analog converter, which can synthesize any composite rf waveform formed by a combination of sine signals. The images are formed thro…
Posting for Consensus, Sharing Consensus. The Case of Migrants on Facebook, Ideological Views and Echo Chambers
2018
This study analyses posts and comments on a popular social network (Facebook) in order to investigate how web-users take advantage of participative platforms to post ideologically-driven comments, and how the exchanges create echo chambers. In particular, the study addresses populism expressed in online debates concerning migrants and used as a pretext to show group identities and ideologies. Facebook is thus taken as an example and considered a participatory platform (Boyd 2014) of political (populist) activism and the milieu for consensus-finding. The dialogic structure of comments is studied within Conversation Analysis adapted to online written texts (Antaki et al. 2005; Giles et al. 20…
Protocolo técnico para la fotografía de fuentes filológicas primarias
2014
con fines documentales, proyectado para garantizar la máxima fidelidad posible al motivo original representado. Tras una descripción detallada del material necesario, seleccionado específicamente en función de las necesidades particulares de la fotografía de textos manuscritos o impresos, se desarrolla un procedimiento adaptado a las nuevas circunstancias de la fotografía digital, concebido en dos fases: la captación de la imagen en formato RAW, y su posterior edición. En este estudio se trata la primera parte, describiendo sistemáticamente, paso a paso, las decisiones técnicas relativas a los ajustes fotográficos de la toma en diferentes situaciones lumínicas, encaminadas a maximizar la ca…
Camera-based measurement of relative image contrast in projection displays
2013
International audience; This research investigated the measured contrast of projection displays based on pictures taken by un-calibrated digital cameras under typical viewing conditions. A high-end radiometer was employed as a reference to the physical response of projection luminance. Checkerboard, gray scale and color complex test images with a range of the projector's brightness and contrast settings were projected. Two local and two global contrast metrics were evaluated on the acquired pictures. We used contrast surface plots and Pearson correlation to investigate the measured contrast versus the projector's brightness and contrast settings. The results suggested, as expected, the proj…
Concerning the calculation of the color gamut in a digital camera
2006
Several methods to determine the color gamut of any digital camera are shown. Since an input device is additive, its color triangle was obtained from their spectral sensitivities and it was compared with the theoretical sensors of Ives-Abney-Yule and MacAdam. On the other hand, the RGB digital data of the optimal or MacAdam colors were simulated to transform them into XYZ data according to the colorimetric profile of the digital camera. From this, the MacAdam limits associated to the digital camera are compared with the corresponding ones of the CIE-1931 XYZ standard observer, resulting that our color device has much smaller MacAdam loci than those of the colorimetric standard observer. Tak…
A combined single range and single image device for low-cost measurement of building facade features
2008
The dimensions of building facades and window apertures are usually determined by making direct measurements using tapes and plummets. This approach, however, has a number of drawbacks including the physical risk to which the persons making the measurements are exposed. This paper proposes an indirect approach based on close range photogrammetry that is inexpensive, simple, fast and safe, and which does not require specialist staff or direct ground control measurements. The method is based on taking a picture using a digital camera and measuring the distance to the object using a handheld laser distance meter. Both items of equipment are mounted on a specially designed support that allows t…
Combined Endo- and Exoscopic Semi-robotic Manipulator System for Image Guided Operations
2006
This paper describes the development of a robotic assistance system for image guided operations. To minimize operation time, a multimodal user interface enables freehand robotic manipulation of an extracorporeal stereoscopic digital camera (exoscope) and an endoscope. The surgeon thereby wears a head-mounted unit with a binocular display, a head tracker, a microphone and earphones. Different view positioning and adjustment modes can be selected by voice and controlled by head rotation while pressing a miniature confirmation button with a finger. Initial studies focused on the evaluation and optimization of the intuitiveness, comfort and precision of different modes of operation, including a…
Characterization of a digital camera as an absolute tristimulus colorimeter
2003
An algorithm is proposed for the spectral and colorimetric characterization of digital still cameras (DSC) which allows them to be used as tele-colorimeters with CIE-XYZ color output, in cd/m2. The spectral characterization consists in the calculation of the color-matching functions from the previously measured spectral sensitivities. The colorimetric characterization consists in trans- forming the raw RGB digital data into absolute tristimulus values CIE-XYZ (in cd/m2) under variable and unknown spectroradiometric conditions. Thus, in the first stage, a gray balance was applied over the raw RGB digital data to convert them into RGB relative colorimetric values. In the second stage, an algo…