Cataractous eye fundus image enhancement by using multi-scale tone decomposition

Abstract

Through optical equipment such as the ophthalmoscope, it is possible to visualize and image the inner surface of the eye, where the main structures of the retina can be observed. The visual analysis of the retinal vasculature is widely used by ophthalmologists for prevention, diagnosis, and monitoring of retinal diseases. Nevertheless, derived from pathologies that generate an opacity in the crystalline lens (such as cataracts), the task of visualize blood vessels becomes difficult, since there is a lack of contrast in the fundus image. In this work, a multiscale decomposition method based on the Weighted Least Squares (WLS) optimization is applied to cataractous eye fundus images, with the aim of obtaining a better blood-vessel to background contrast. The proposed scheme is implemented over a publicly-available cataract eye fundus dataset. The experimental results provide a notorious visual improvement in contrast and restoration of blood vessels pixels and, in addition, maintains adequate saturation and lighting for visual analysis. The visual improvement of the vasculature represents a potential benefit in the ophthalmic analysis of patients with cataracts, since it is possible to observe the vascular morphology in greater detail while keeping relevant image features.