Introduction: Diabetic retinopathy (DR) is the single largest cause of sight loss and blindness in the working age population of Western countries; it is the most common cause of blindness in adults between 20 and 60 years of age. Early diagnosis of DR is critical for preventing vision loss so early detection of microaneurysms (MAs) as the first signs of DR is important. This paper addresses th...

The azimuth of a stimulus relative to the head can be determined from an extra-retinal, eye-position signal plus an estimate of the retinal eccentricity of the image. Alternatively, azimuth could be determined from retinal-image information alone. Specifically, stimulus azimuth could be estimated from two derivatives of vertical disparity: vertical size ratio (which varies with azimuth), and th...

It has been argued that when an observer moves, a contingent retinal-image motion of a stimulus would strengthen the perceived glossiness. This would be attributed to the veridical perception of three-dimensional structure by motion parallax. However, it has not been investigated whether the effect of motion parallax is more than that of retinal-image motion of the stimulus. Using a magnitude e...

Purpose: Retinal image registration is a useful tool for medical professionals. However, evaluating the accuracy of these registrationmethods has not been consistently undertaken in the literature. To address this, a dataset comprised of retinal image pairs annotated with ground truth and an evaluation protocol for registration methods is proposed. Methods: The dataset is comprised of 134 retin...

Introduction: This paper addresses a method for automatic detection of blood vessels in color fundus images which utilizes two main tools: image partitioning and local Radon transform. Material and Methods: The input images are firstly divided into overlapping windows and then the Radon transform is applied to each. The maximum of the Radon transform in each window corresponds to the probable a...

The extraction of blood vessels from retinal images is an important and challenging task in medical analysis and diagnosis. This paper presents a novel hybrid automatic approach for the extraction of retinal image vessels. The method consists in the application of mathematical morphology and a fuzzy clustering algorithm followed by a purification procedure. In mathematical morphology, the retin...

This paper describes a computer program for calculating the contrast image on the human retina from an array of scene luminances. We used achromatic transparency targets and measured test target's luminances with meters. We used the CIE standard Glare Spread Function (GSF) to calculate the array of retinal contrast. This paper describes the CIE standard, the calculation and the analysis techniq...

The exploration of retinal vessel structure is colossally important on account of numerous diseases including stroke, Diabetic Retinopathy (DR) and coronary heart diseases, which can damage the retinal vessel structure. The retinal vascular network is very hard to be extracted due to its spreading and diminishing geometry and contrast variation in an image. The proposed technique consists of un...

In this paper presents , segmentation of blood vessels in retinal images based on neural network (NN) scheme of gray-level and moment invariants-based features. In the past, rural based methods are used segment the blood vessels. It has more complexity and less accuracy of blood vessels detection in retinal images. This paper proves better performance in terms of blood vessel detection in stare...

Herein we present the spectral-domain optical coherence tomographic (SD-OCT, Heidelberg Spectralis; Heidelberg Engineering, Heidelberg, Germany) image of an 80-year-old male patient with partial posterior vitreous detachment (PVD). Tractional forces from the vitreous body pull retinal layers by means of vitreoretinal adhesions.1,2 This high-resolution SD-OCT image illustrates how traction eleva...