Enhancement of color retinal images in poor imaging conditions

Abstract

Aberrations are one of the two main optical phenomena degrading the retinal image's quality. As light propagates to and from the retina, it will be scattered by small inhomogeneities within the ocular media. The amount of scattering in a young non pathological eye is low but increases with age and some pathologies (e.g. cataract). This increased scattering results in a degradation of the retinal image in terms of reduced brightness, poorer contrast, colour degradation and possibly lower spatial resolution. This phenomenon is similar to the degradation of images caused by atmospheric conditions. Although a large body of work exists on the enhancement of images recorded in poor visibility conditions, a paucity of papers have focused on reducing the degradation of retinal images by intraocular scattering. This work's aim was to adapt and assess the potential of an automatic defogging system to retinal imaging.