Résumé
This paper describes a portable High Dynamic Range (HDR) imaging system for visually impaired people, intended to display contrast enhanced images of real world environment. The device is composed of a digital camera and head mounted display (HMD) equipped with high resolution screens. The camera is mounted on the HMD to acquire the ambient scene, the acquired images are processed to generate HDR images through the control of local luminance information. The contrast enhancement method adopted in our system is based on pyramidal image contrast structure representation that relies on the local band-limited contrast definition. The imaging system we propose aims at displaying images that meet the visual capabilities related to contrast sensitivity of people with low vision. It also provides a solution to alleviate discomfort problem expressed by these people when they are facing real-world changing light conditions.