NON INVASIVE IMAGE CONTRAST ENHANCEMENT TECHNIQUE FOR RETINAL FUNDUS IMAGES

The analysis of retinal vasculature in digital fundus images is important for
diagnosing eye related diseases in particular, diabetic retinopathy (DR). However,
digital colour fundus images suffer from low and varied contrast. With added
presence of noise it becomes difficult to analyse retinal vasculature digitally requiring
the use of fundus angiogram modality. The fundus fluorescein angiogram (FFA)
modality gives 5 to 6 time's higher contrast for the retinal vasculature but it is an
invasive method (injection of contrasting dyes) that can lead to other physiological
problems.—A reported digital image enhancement technique named RETICA thai
combines Retinex and ICA techniques, reduces varied contrast, and enhances the low
contrast blood vessels of model fundus images.