to investigate the effect of preprocessing techniques including contrast enhancement and illumination correction on retinal imagequality, a comparative study was carried out. we studied and implemented a few illumination correction and contrast enhancementtechniques on color retinal images to find out the best technique for optimum image enhancement. to compare and choose thebest illumination c...

diabetic retinopathy is one of the most important reasons of blindness which causes serious damage in the retina. the aim of this research is to detect one lesions of the retina, named exudates automatically with image processing techniques. preprocessing is the first step of proposed algorithm. after preprocessing, the optic disc was detected and removed from the retinal image due to the same ...

In this paper we consider the problem of blood vessel segmentation in retinal images. After enhancing the retinal image we use green channel of images for segmentation as it provides better discrimination between vessels and background. We consider the negative of retinal green channel image as a topographical surface and extract ridge points on this surface. The points with this property are l...

This paper presents an automated method for detecting microaneurysms in the retinal angiographic images by using image processing techniques. In the presented method, in order to fade or remove the pseudo images, first retinal images are pre-processed. Then microaneurysms are identified by circular Hough transform. In the existing methods of dete...

This paper presents an automated method for detecting microaneurysms in the retinal angiographic images by using image processing techniques. In the presented method, in order to fade or remove the pseudo images, first retinal images are pre-processed. Then microaneurysms are identified by circular Hough transform. In the existing methods of dete...

detecting blood vessels is an important task in retinal image analysis.  the task is more challenging with the presence of bright and dark lesions in retinal images. here, a method is proposed to detect vessels in both normal and abnormal retinal fundus images based on their linear features. first, the negative impact of bright lesions is reduced by using k-means segmentation in a perceptive sp...