Search results for "LED illumination"
showing 5 items of 5 documents
Comparison of single-spot technique and RGB imaging for erythema index estimation
2016
A commercially available point measurement device, the Mexameter(®), and an experimental RGB imaging prototype device were used for erythema index estimation of 50 rosacea patients by analysing the level of skin redness on the forehead, both cheeks and both sides of a nose. Results are compared with Clinician's Erythema Assessment (CEA) values given by two dermatologists. The Mexameter uses 568 nm and 660 nm LEDs and a photodetector for estimation of erythema index, while the used prototype device acquired RGB images at 460 nm, 530 nm and 665 nm LED illumination. Several erythema index estimation algorithms were compared to determine which one gives the best contrast between increased eryth…
Towards to deep neural network application with limited training data: synthesis of melanoma's diffuse reflectance spectral images
2019
The goal of our study is to train artificial neural networks (ANN) using multispectral images of melanoma. Since the number of multispectral images of melanomas is limited, we offer to synthesize them from multispectral images of benign skin lesions. We used the previously created melanoma diagnostic criterion p'. This criterion is calculated from multispectral images of skin lesions captured under 526nm, 663nm, and 964nm LED illumination. We synthesize these three images from multispectral images of nevus so that the p' map matches the melanoma criteria (the values in the lesion area is >1, respectively). Demonstrated results show that by transforming multispectral images of benign nevus i…
FPI Based Hyperspectral Imager for the Complex Surfaces : Calibration, Illumination and Applications
2022
Hyperspectral imaging (HSI) applications for biomedical imaging and dermatological applications have been recently under research interest. Medical HSI applications are non-invasive methods with high spatial and spectral resolution. HS imaging can be used to delineate malignant tumours, detect invasions, and classify lesion types. Typical challenges of these applications relate to complex skin surfaces, leaving some skin areas unreachable. In this study, we introduce a novel spectral imaging concept and conduct a clinical pre-test, the findings of which can be used to develop the concept towards a clinical application. The SICSURFIS spectral imager concept combines a piezo-actuated Fabry–Pé…
Development of a High Irradiance LED Configuration for Small Field of View Motion Estimation of Fertilizer Particles
2015
International audience; Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective …
Quantitative Multispectral Imaging Differentiates Melanoma from Seborrheic Keratosis.
2021
Melanoma is a melanocytic tumor that is responsible for the most skin cancer-related deaths. By contrast, seborrheic keratosis (SK) is a very common benign lesion with a clinical picture that may resemble melanoma. We used a multispectral imaging device to distinguish these two entities, with the use of autofluorescence imaging with 405 nm and diffuse reflectance imaging with 525 and 660 narrow-band LED illumination. We analyzed intensity descriptors of the acquired images. These included ratios of intensity values of different channels, standard deviation and minimum/maximum values of intensity of the lesions. The pattern of the lesions was also assessed with the use of particle analysis. …