Monitoring paint and primer samples using multispectral and hyperspectral imaging techniques

International audienc

Using light to facilitate the mobility of low vision people

International audienceTwo thirds of the low vision population are over the age of 50 and were not concerned by any visual deficiency when they were younger. The predominant concerns of the largest part of such a population are the loss of independence and the ability to perform simple activities of everyday life. With a clear lack of efficient visual aids, one urgent challenge is to design and to develop new approaches to facilitate the vision rehabilitation, the mobility and the socioeconomic independence of people that have to face a visual impairment inducing major changes in their life. Within this framework, we investigated the influence of lighting-based edge enhancement techniques on the autonomous mobility of visually impaired people

Appearance of Gemstones and the Objective Assessment of Its Modification Caused by Irradiation and Heating Treatments

International audienc

Contrast of colored pairs enhanced by using 3 selective wavelengths for people with low vision

International audienc

Colour discrimination for visually impaired people under mixed light LEDs and white LEDs

Visual impairment, a spectrum ranging from moderate visual acuity to blindness, poses significant challenges to daily living, social interactions, and employment opportunities. People with visual impairments often require specialised support and accommodations to engage fully in society. One critical aspect of vision, especially for those with mild to moderate visual impairment, is colour discrimination, which plays a pivotal role in object recognition and classification based on chromatic properties. This study investigates the effectiveness of a mixed light LED (RGB+YW) with a colour temperature of 5000K compared to two controlled Light Emitting Diode (LED) lamps with warm white (4000K) and cool white (6500K) illumination in enhancing colour discrimination for individuals with mild and moderate visual impairment.Three different illuminance levels (20 lux, 200 lux, and 2000 lux) were considered, and the study involved thirty simulated participants representing mild and moderate visual impairment. Simulated mild visual impairment was achieved using cloudy lenses with a visual acuity of 6/12, while simulated moderate visual impairment involved clear lenses with a visual acuity of 6/18. The Farnworth-Munsell 100 hue test served as the stimulus for colour discrimination evaluation.The results demonstrated a significant reduction in the Total Error Score (TES) of colour discrimination as illuminance levels increased. At higher illuminance levels (200 lux and 2000 lux), the differences in performance among the light sources diminished. However, at the lower illuminance level of 20 lux, the mixed light LED outperformed both controlled white LED lamps. Interestingly, participants with similar simulated visual impairments did not exhibit consistent patterns on the polar scale of the Farnworth-Munsell 100 hue test. Additionally, it was observed that despite having lower visual acuity, individuals with simulated mild visual impairment (cloudy lenses) had higher average TES scores compared to those with simulated moderate impairment (clear lenses) at certain illumination levels. These findings underscore the significant impact of illumination levels on colour discrimination for individuals with low vision. With its specific wavelength selection, the mixed light LED shows promise in enhancing colour discrimination for individuals with mild and moderate visual impairment, particularly in low-light conditions, outperforming controlled white LED lamps. This study contributes valuable insights into improving the visual experiences of individuals with visual impairments, facilitating better participation in daily activities and professional settings

Does illumination affect mobility of people with low vision?

International audienc

Threshold of luminance contrast and chromaticity contrast for subjects wearing simulated low vision glasses

International audienc

Optimized coloured light for enhancing colour discrimination in blurred and cloudy visions

International audienc

Mutual Illumination and Color Constancy

International audienc

A multichannel LED-based lighting approach to improve color discrimination for low vision people

International audienceThe population of low vision people increases continuously with the acceleration of aging society. As reported by the World Health Organization (WHO), most of this population is over the age of 50 years and 81% were not concerned by any visual problem before. A visual deficiency can dramatically affect the quality of life and challenge the preservation of a safe independent existence.This study presents a LED-based lighting approach to assist people facing an age-related visual impairment. The research procedure is based on a psychophysical experiment consisting in the ordering of standard color samples. Volunteers wearing low vision simulation goggles performed such an ordering under different illumination conditions produced by a 24-channel multispectral lighting system. A filtering technique using color rendering indices coupled with color measurements allowed to objectively determine the lighting conditions providing the best scores in terms of color discrimination.Experimental results demonstrated that white light obtained by a special mixing of three selected channels can improve the color perception of low vision people in comparison to white LEDs nowadays available on the market for general lighting. Even if additional studies are required to go further, these first results give hope for the design of smart lighting devices that might adapt to the visual needs of the visually impaired