The goal of image enhancement is to improve the visual appearance of the image. For this purpose we are using two methods to compute the image background using morphological transformations. Contrast enhancement in grey level images with poor lighting can be achieved by two operators based on Weber’s law. The one operator employs information from block analysis and the other utilizes the openin...

We present a hierarchical neurodynamical system for object recognition based on attentional control of the spatial resolution with which an object is analyzed during an iterative hypothesis testing cycle. Psychophysical evidence strongly suggests that attentional processing results in the enhancement of the spatial resolution in the input region corresponding to the focus of attention. We adopt...

Background: The major limitation in human vision is refractive error. Auxiliary equipment and methods for these people are not always available. In addition, limited range of accommodation in adult people when switching from a far point to a near point is not simply possible. In this paper, we are looking for solutions to use the facilities of digital image processing and displaying to improve ...

The role of subcortical visual structures such as the lateral geniculate nucleus (LGN) and the superior colliculus (SC) in the control of visual spatial attention remains poorly understood. Here, we used high-resolution functional magnetic resonance imaging to measure responses in the human LGN and SC during sustained spatial attention. Subjects covertly and continuously tracked one of two segm...

One ubiquitous finding in functional magnetic resonance imaging studies is that repeated stimuli elicit lower responses than novel stimuli. In apparent contradiction, some studies have reported the exact opposite effect--greater responses to repeated than novel stimuli--in many of the same brain regions. Interestingly, these latter enhancement effects are typically obtained when stimuli have be...

In mammals, non-visual responses to light have been shown to involve intrinsically photosensitive retinal ganglion cells (ipRGC) that express melanopsin and that are modulated by input from both rods and cones. Recent in vitro evidence suggests that melanopsin possesses dual photosensory and photoisomerase functions, previously thought to be a unique feature of invertebrate rhabdomeric photopig...

The basis for individual differences in the degree to which visual speech input enhances comprehension of acoustically degraded speech is largely unknown. Previous research indicates that fine facial detail is not critical for visual enhancement when auditory information is available; however, these studies did not examine individual differences in ability to make use of fine facial detail in r...

We describe an automated edge enhancement procedure that operates in conjunction with clustereddot dithering, edge weighted unsharp masking, compound anisotropic diffusion etc. The goal is to make weak edges more noticeable and to give the strong edges in the half toned image a sharper and more natural appearance. Unsharp masking that is widely used for image enhancement amplifies image contras...

In MPEG-4 scalable video coding, only a small portion of input data is coded in the base layer, and most signal components remain in enhancement layers. In this paper, we propose a new frequency weighting method to send more sensitive frequency coefficients faithfully with respect to the human visual system (HVS). In order to implement the frequency weighting method by bit-plane coding, we obta...