Search results for "snapshot"
showing 10 items of 23 documents
A snapshot multi-wavelengths imaging device for in-vivo skin diagnostics
2020
A portable proof-of-concept prototype device for single snapshot capturing of four spectral line images has been designed, assembled and laboratory-tested. It comprises optical unit that ensures even illumination of the skin target area simultaneously at four laser wavelengths - 450 nm, 523 nm, 638 nm and 850 nm, double-camera image recording system, micro-computer managed operation system and a touch-screen display for image control and displaying the concentration distribution maps of four skin chromophores - melanin, oxy-hemoglobin, deoxy-hemoglobin and bilirubin. Besides, the device captures skin auto fluorescence image at 405 nm laser excitation to separate seborrheic keratosis from ot…
La mirada como espejo: diálogos entre Diane Arbus y Nan Goldin
2013
Las instantáneas de Diane Arbus y Nan Goldin no han dejado indiferente a ninguna generación desde sus primeros pasos en la disciplina. Su mención en antologías o historias generales de la fotografía constituye actualmente un compromiso ineludible como hitos de un género fronterizo entre lo artístico y lo documental. Sus figuras y su producción han sido objeto de monografías, estudios críticos, biografías, documentales, filmes y exposiciones en todo el mundo. Hasta el momento, la literatura artística ha conectado sistemáticamente la obra de ambas, sin embargo, no se ha llevado a cabo un análisis íntegro de sus analogías y diferencias. El presente Trabajo Final de Máster ofrece un estudio rel…
Hypervisor-assisted Atomic Memory Acquisition in Modern Systems
2019
Reliable memory acquisition is essential to forensic analysis of a cyber-crime. Various methods of memory acquisition have been proposed, ranging from tools based on a dedicated hardware to software only solutions. Recently, a hypervisor-based method for memory acquisition was proposed (Qi et al., 2017; Martignoni et al., 2010). This method obtains a reliable (atomic) memory image of a running system. The method achieves this by making all memory pages non-writable until they are copied to the memory image, thus preventing uncontrolled modification of these pages. Unfortunately, the proposed method has two deficiencies: (1) the method does not support multiprocessing and (2) the method does…
Snapshot multi-spectral-line imaging for applications in dermatology and forensics
2019
Performance of multi-spectral imaging critically depends on image acquisition time and working spectral bandwidths. Ultimate performance can be achieved if a set of monochromatic (single-wavelength) spectral images is obtained by a single snapshot - a technique provisionally called “snapshot multi-spectral-line imaging” or SMSLI. The SMSLI principle and the developed prototype devices for 3, 4 and 5 spectral line snapshot imaging are described. Two potential practical applications of SMSLI are discussed – for fast mapping of the main in-vivo skin chromophores and for detection of counterfeit banknotes and documents.
Laser illumination designs for snapshot multi-spectral-line imaging
2019
For multi-spectral imaging, both acquisition time of the spectral image set and the spectral bandwidth of each image have to be minimized. Ultimate performance can be achieved if the set of monochromatic (single-wavelength) spectral images is obtained with a single snapshot — a technique provisionally called "snapshot multi-spectral-line imaging" or SMSLI. Using contemporary RGB colour cameras, up to three spectral line images can be extracted from a snapshot image data cube at specific illumination that comprises only three spectral lines, each of them positioned within one of the detection bands (R, G or B) [1]. Techniques able to provide more spectral line images are under development, a…
Single snapshot RGB multispectral imaging at fixed wavelengths: proof of concept
2014
A concept of single snapshot multispectral imaging by standard RGB image sensors under spectrally-specific illumination comprising a fixed number of narrow spectral lines is discussed and experimentally validated. The limiting conditions, RGB band spectral crosstalk corrections and potential applications for parametric mapping of skin are regarded, along with the preliminary results of the proof-of-concept measurements.
Recurrent gastrointestinal haemorrhage from the distal duodenum
2006
In October 2004, a 69 year female patient presented with melena and anaemia (haemoglobin level 9 g/dl). The patient had been on warfarin due to construction of an aorto-bifemoral graft because of an aortic aneurysm and an …
3×3 Technique for RGB Snapshot Mapping of Skin Chromophores
2015
Three monochromatic spectral images have been extracted from a single RGB image data set at simultaneous illumination of skin by 473nm, 532nm and 609nm spectral lines. They were further transformed into distribution maps of three skin chromophores - melanin, oxy-hemoglobin and deoxy-hemoglobin, related to pigmented and vascular skin malformations. Performance and clinical potential of the proposed 3×3 technique is discussed.
Smartphone single-snapshot mapping of skin chromophores
2016
Suitability of smartphone for single-snapshot mapping of skin melanin, oxy-hemoglobin and deoxy-hemoglobin under 3-wavelengths illumination was demonstrated. Simultaneous 448-532-659 nm illumination was provided by a portable laser-based prototype.
Snapshot Spectral Imaging
2018
This chapter describes an application of the spline-based wavelet frames to the spectral imaging. It presents a method that enables to convert a regular digital camera into a snapshot spectral imager by equipping the camera with a dispersive diffuser and with a compressed sensing-based algorithm for digital processing. The method relies on the assumption that typical images can be sparsely represented in the frame domain. The solution is found from the constrained \(l_{1}\) minimization of a functional by Bregman iterations. Results of optical experiments are reported. The chapter is based on the paper (Golub et al., Appl. Opt. 55, 432–443, (2016), [11]).