Search results for "SPECTRA"
showing 10 items of 3542 documents
Editorial for the Special Issue “Frontiers in Spectral Imaging and 3D Technologies for Geospatial Solutions”
2019
This Special Issue hosts papers on the integrated use of spectral imaging and 3D technologies in remote sensing, including novel sensors, evolving machine learning technologies for data analysis, and the utilization of these technologies in a variety of geospatial applications. The presented results showed improved results when multimodal data was used in object analysis.
Multidimensional Optical Sensing and Imaging Systems (MOSIS): From Macro to Micro Scales
2017
Multidimensional optical imaging systems for information processing and visualization technologies have numerous applications in fields such as manufacturing, medical sciences, entertainment, robotics, surveillance, and defense. Among different three-dimensional (3-D) imaging methods, integral imaging is a promising multiperspective sensing and display technique. Compared with other 3-D imaging techniques, integral imaging can capture a scene using an incoherent light source and generate real 3-D images for observation without any special viewing devices. This review paper describes passive multidimensional imaging systems combined with different integral imaging configurations. One example…
Mobile platform for online processing of multimodal skin optical images: Using online Matlab server for processing remission, fluorescence and laser …
2015
Mobile platform for multimodal skin assessment has been developed. Different illumination sources allow switching between modalities. Diffuse reflectance spectral imaging is provided by five LEDs, fluorescence is excited by 405 nm LEDs, and laser speckle by 650 nm laser diode. Handheld, battery powered device includes all light sources and color camera with USB. The core of the system is Linux OS embedded microcontroller. USB, FTP and HTML with JavaScript combination is used to create standard image transfer and control interface. In combination with built in WiFi access point it allows online skin images storage and processing. It means that data processing algorithms are located and updat…
Diffuse reflectance and fluorescence multispectral imaging system for assessment of skin
2014
The diffuse reflectance multispectral imaging technique has been used for distant mapping of in vivo skin chromophores (hemoglobin and melanin). The fluorescence multispectral imaging is not so common for skin applications due to complicity of data acquisition and processing, but could provide additional information about skin fluorophores. Both techniques are compatible, and could be combined into a multimodal solution. The multispectral imaging system Nuance based on liquid crystal tunable filters was adapted for diffuse reflectance and fluorescence spectral imaging of in vivo skin. Uniform illumination was achieved by LED ring light. Combination of four LEDs (warm white, 770 nm, 830 nm a…
Water detection in skin by dual-band photodiodes
2013
Purpose of this study was to develop a simple model for possibilities to detect water in skin by diffuse reflectance spectra. The model is based on comparison of diffuse reflectance spectra when illuminating water sample with LEDs of different wavelengths (1200 nm, and 1450 nm). The illumination LEDs were chosen due to water absorption differences in near-infrared spectral range. For detection, dual-band photodiode DSD2 by Thorlabs was used. Due to differences of water absorption at different wavelengths in the near-infrared spectral region, this correlation could be used for mapping of water content in skin or, in other words, determine relative moisture level in skin. Simple experimental …
Skin haemoglobin mapping: comparison of multi-spectral imaging and selective R-G-B analysis
2010
The multi-spectral imaging technique has been used for distant mapping of in-vivo skin haemoglobin. Besides, potential of selective R-G-B analysis of skin images has been studied under bi-chromatic (532 nm and 635 nm) laser illumination.
Determination of chromophore distribution in skin by spectral imaging
2012
Possibilities to determine chromophore distribution in skin by spectral imaging were explored. Simple RGB sensor devices were used for image acquisition. Totally 200 images of 40 different bruises of 20 people were obtained in order to map chromophores bilirubin and haemoglobin. Possibilities to detect water in vitro and in vivo were estimated by using silicon photodetectors and narrow band LEDs. The results show that it is possible to obtain bilirubin and haemoglobin distribution maps and observe changes of chromophore parameter values over time by using a simple RGB imaging device. Water in vitro was detected by using differences in absorption at 450 nm and 950 nm, and 650 nm and 950 nm.
Optical quality of intraocular lenses after several years in the human eye
2013
The optical quality of explanted intraocular lenses (IOLs) was analysed to verify if their quality is maintained after having been in the human eye for several years. Twenty-five explanted IOLs were studied, 10 because of intraocular luxation and 15 from corneal donors. The dioptric power and modulation transfer function (MTF) were determined to discover the image quality of the IOLs. The spectral transmission was also established to ascertain whether the filter against ultraviolet (UV) radiation was still effective. The results show that the MTF of implanted IOLs is maintained and therefore so is the image quality they provide. Only decay in the MTF of some of the explanted IOLs was observ…
Evaluation of Skin Melanoma in Spectral Range 450-950 nm Using Principal Component Analysis
2013
Diagnostic potential of principal component analysis (PCA) of multi-spectral imaging data in the wavelength range 450-950 nm for distant skin melanoma recognition is discussed. Processing of the measured clinical data by means of PCA resulted in clear separation between malignant melanomas and pigmented nevi.
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.