The function of the low-level image processing that takes place in the biological retina is to compress only the relevant visual information to a manageable size. The behavior of the layers and different channels of the neuromorphic retina has been successfully modeled by cellular neural/nonlinear networks (CNNs). In this paper, we present an extended, application-specific emulated-digital CNN-...

Both vertebrate and invertebrate retinas are highly efficient in extracting contrast independent of the background intensity over five or more decades. This efficiency has been rendered possible by the adaptation of the DC operating point to the background intensity while maintaining high gain transient responses. The centersurround properties of the retina allows the system to extract informat...

Silicon retinas are typically implemented with multiple photosensors. Recent work with VLSI extended analog computers has led to a single-photosensor retina. It is called a continuous retina because the image focused on it generates a current gradient within the sensor, as opposed to independent currents in multiple sensors. The current gradient is discretized into an analog output vector, then...

Retinal detachment, the separation of retina from the retinal pigmented epithelium caused by eye injury, has been studied extensively for decades [1]. It causes many cellular changes inside the retina tissue, which could significantly affect the structure, state and function of the retinal tissues, thus may cause the loss of vision. In order to devise therapies for retinal detachment, extensive...

Diabetic retinopathy lesion detection such as exudate in fundus image of retina can lead to early diagnosis of the disease. Retinal image includes dark areas such as main blood vessels and retinal tissue and also bright areas such as optic disk, optical fibers and lesions e.g. exudate. In this paper, a multistage algorithm for the detection of exudate in foreground is proposed. The algorithm se...

Biometric system is a pattern-recognition system that recognizes a person based on the personal physiological or behavioural characteristics that the person possesses. Human retina, one source of biometric provides the most reliable and with the emerging potentials of automated image processing a highly secure means of authentication is possible. The proposed system describes the development of...

This paper describes a novel method to resample cartesian images to a retina-like hexagonal tessellation, consisting of foveal and peripheral regions. We introduce the inflated-hexagons model for the foveal region resampling, which has an efficient data structure for storage and mapping of cortical coordinates. The integral image representation is used as intermediate step for the peripheral re...