This paper proposes a method for the Retinal image analysis through efficient detection of exudates and recognizes the retina to be normal or abnormal. The contrast image is enhanced by curvelet transform. Hence, morphology operators are applied to the enhanced image in order to find the retinal image ridges. A simple thresholding method along with opening and closing operation indicates the re...

Images of the eye ground or retina not only provide an insight to important parts of the visual system but also reflect the general state of health of the entire human body. Automated retina image analysis is becoming an important screening tool for early detection of certain risks and diseases like diabetic retinopathy, hypertensive retinopathy, age related macular degeneration, glaucoma etc. ...

A retinal image has blood vessels, optic disc, fovea, and so forth as the main components of an image. Segmentation of these components has been investigated extensively. Principal component analysis (PCA) is one of the techniques that have been applied to segment the optic disc, but only a limited work has been reported. To our knowledge, fovea segmentation problem has not been reported in the...

PURPOSE To investigate the optical intensities of all retinal layers on three-dimensional (3D) spectral-domain optical coherence tomography (SD-OCT) in normal subjects using an automatic measurement. METHODS Forty normal subjects underwent Topcon 3D OCT-1000 macula-centered scan. The raw data were automatically segmented into 10 layers using the 3D graph search approach. Then the mean and sta...

McCloskey and a team of authors (1995) documented a fascinating deficit involving the localization of objects. When subject A.H. reaches for objects placed in different positions, she is often wrong about direction but not amount. An object located 30° to her left, say, might cause her to reach 30° to the right. The authors demonstrated that her motor abilities are flawless and that the errors ...

Filtering belongs to the most fundamental operations of retinal image processing and for which the value of the filtered image at a given location is a function of the values in a local window centered at this location. However, preserving thin retinal vessels during the filtering process is challenging due to vessels' small area and weak contrast compared to background, caused by the limited r...

11 Existing algorithms based on scale invariant feature transform (SIFT) and Harris corners such as edge-driven 12 dual-bootstrap iterative closest point and Harris-partial intensity invariant feature descriptor (PIIFD) respectivley have 13 been shown to be robust in registering multimodal retinal images. However, they fail to register color retinal 14 images with other modalities in the presen...

In the clinical refraction of the eye, aniseikonia and anisometropia are inevitably used terms. Image formation and its retinal size is the function of the power of the dioptric eye system. However, the correcting lens in front of the eye and the eye optical system represent a unique optical afocal system, in which the distance between correcting lens and corneal vertex is of utmost importance,...

PURPOSE To evaluate the performance of an automated retinal image quality assessment system for use in automated diabetic retinopathy grading. METHODS Algorithmic methods have been developed for assessing the quality of 45 degrees single field retinal images for use in diabetic retinopathy screening. For this purpose, image quality was defined by two aspects: image clarity and field definitio...

Several signaling pathways and transcription factors control the cell fate in its in vitro development and differentiation. The orchestrated use of these factors results in cell specification. In coculture methods, many of these factors secrete from host cells but control the process. Today, transcription factors required for retinal progenitor cells are well known, but the generation of these ...