Optic disk segmentation is a prerequisite step in automatic retinal screening systems. In this paper, we propose an algorithm for optic disk segmentation based on a local adaptive thresholding method. Location of the optic disk is validated by intensity and average vessel width of retinal images. Then an adaptive thresholding is applied on the temporal and nasal part of the optic disc separatel...

In this paper we introduced new wavelet based algorithm for speckle reduction of synthetic aperture radar images, which uses combination of undecimated wavelet transformation, wiener filter (which is an adaptive filter) and mean filter. Further more instead of using existing thresholding techniques such as sure shrinkage, Bayesian shrinkage, universal thresholding, normal thresholding, visu thr...

A short review of wavelet-based adaptive methods for modeling and simulation incompressible turbulent flows is presented. Wavelet-based computational approaches different fidelities are recast into an integrated hierarchical eddy-capturing turbulence framework. The wavelet threshold filtering procedure the associated wavelet-filtered Navier–Stokes equations briefly discussed, along with colloca...

In this paper we introduced new wavelet based algorithm for speckle reduction of synthetic aperture radar images, which uses combination of undecimated wavelet transformation, wiener filter (which is an adaptive filter) and mean filter. Further more instead of using existing thresholding techniques such as sure shrinkage, Bayesian shrinkage, universal thresholding, normal thresholding, visu thr...

Thresholding is a simple but effective technique for image segmentation. In this paper, a general locally adaptive thresholding method using neighborhood processing is presented. The method makes use of local image statistics of mean and variance within a variable neighborhood and two thresholds obtained from the global intensity distribution. It can thus take advantage of local thresholding an...

With the recent development of wavelet-based techniques for computational fluid dynamics, adaptive numerical simulations of turbulent flows have become feasible [1]. Adaptive wavelet methods are based on wavelet threshold filtering that makes it possible to separate coherent energetic eddies, which are numerically simulated, from residual background flow structures that are filtered out. By var...

Image thresholding is used to segment an image into background and foreground using a given threshold. The threshold can be generated specific algorithm instead of pre-defined value obtained from observation or experiment. However, the involves per pixel operation, histogram calculation, iterative procedure search optimum that costly for high-resolution images. In this research, parallel implem...