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Ocular images processing is an important task in: i) biometrics system based on retina and/or sclera images, and ii) in clinical ophthalmology diagnosis of diseases like various vascular disorders. We presents a general framework for image processing of ocular images with a particular view on feature extraction. The method uses the set of geometrical and texture features and based on the inform...

Vertebrate eyes are of the simple or camera type with a single optical system that creates an image on the retina in the back of the eye. There, the visual information is encoded as nervous signals by photoreceptors, processed by retinal neurons, and then sent to the brain via the optic nerve. Surprisingly at first sight, the retinal neurons are located between the lens and the light-sensitive ...

Standard models of stimulus encoding in the retina postulate that image presentations activate neurons according to the increase of preferred contrast inside the receptive field. During natural vision, however, images do not arrive in isolation, but follow each other rapidly, separated by sudden gaze shifts. We here report that, contrary to standard models, specific ganglion cells in mouse reti...

This paper describes an algorithm to continually and accurately estimate the absolute location of a diagnostic or surgical tool (such as a laser) pointed at the human retina, from a series of image frames. We treat the problem as a registration problem, using diagnostic images to build a spatial map of the retina and then registering each on-line against this map. Since the image location where...

One of the most striking aspects of visual experience is the ease with which we make sense of motion in the world. The apparent ease with which motion is perceived can obscure the fact that the visual system is faced with a formidable set of problems in processing visual motion. At the physical level, movement in the world causes changes in the distribution of light across the retina. Somehow t...

An optical model for imaging the retina through cataracts has been developed. The images are treated as sample functions of stochastic processes. On the basis of the model a homomorphic Weiner filter can be designed that will optimally restore the cataractous image (in the mean-square-error sense). The design of the filter requires a priori knowledge of the statistics of either the cataract tra...