Weighted median filters (smoothers) have been shown to be analogous to normalized FIR linear filters constrained to have only positive weights. In this paper, it is shown that much like the mean is generalized to the rich class of linear FIR filters, the median can be generalized to a richer class of weighted median (WM) filters admitting positive and negative weights. The generalization follow...

In this paper, we present a spatially adaptive filter for color median filtering. Several alternative implementations of such a filter are given, using different ways of gradient computation. Then, several methods of color median filtering are compared in terms of performance on a particular image. Vector median filters are considered as well as median filters inspired by grey-

This paper deals with median filtering techniques suitable for digital color images. Median filters have successfully been used in gray scale imaging to remove impulsive noise but their extension to color images is not direct. The main difficulty is that an order has to be defined to sort the color vectors. In this paper, we selected four classical different and well established approaches prop...

In this paper, we proposed a new adaptive median filter for image denoising. In our method, two thresholds have been involved for detecting noises in variable-sized windows. The median filter and the mean filter are combined for changing the value of the corrupted pixels. The filter can preserve the fine details of image while suppressing the impulsive-type noise. The results of the experiments...

In this paper, we present a median filter which uses an adaptive variable block. The two dimension median filter is a nonlinear digital image filtering method, which generally used to remove unwanted impulse noise. The median filter is normally used in the step of pre-processing to improve the performance. To assess performance of the proposed method, we vary noise level and block size. Experim...

to investigate the effect of preprocessing techniques including contrast enhancement and illumination correction on retinal imagequality, a comparative study was carried out. we studied and implemented a few illumination correction and contrast enhancementtechniques on color retinal images to find out the best technique for optimum image enhancement. to compare and choose thebest illumination c...

Existing state-of-the-art switching-based median filters are commonly found to be nonadaptive to noise density variations and prone to misclassifying pixel characteristics at high noise density interference. This reveals the critical need of having a sophisticated switching scheme and an adaptive weighted median filter. We propose a novel switching-based median filter with incorporation of fuzz...

This paper presents a new cost-effective, adaptive multichannel filter taking advantage of switching schemes, robust order-statistic theory and approximation of the multivariate dispersion. Introducing the statistical control of the switching between the vector median and the identity operation, the developed filter enhances the detail-preserving capability of the standard vector median filter....

In response to the flaw that the median filtering algorithm has a poor handling capacity to high-density and fine texture noise, a Dynamic window-based adaptive median filter algorithm is proposed. According to the associated level between noise-point information and the surrounding, the new algorithm adjust, the Noise point filter value, which can get a better deal with the details of the imag...

Medical images like ultrasound images are generally corrupted by speckle noise during their acquisition and transmission. The impact of speckle noise reduces the diagnostic value of the medical image modality. Thus, a speckle noise reduction technique is necessary for the suppression of noise and to retain the fine details from the corrupted image. In this article, a new speckle noise reduction...