Within the last two decades a small group of researchers has built a useful, nontrivial theory of nonlinear signal processing around the median-related filters known as rank-order filters, order-statistic filters, weighted median filters, and stack filters. This required significant effort to overcome the bias, both in education and research, toward linear theory, which has been dominant since ...

This paper presents a new method for filtering the impulse noise in images. This is a two-stage approach in which an impulse is first detected by thresholding the energy of the prediction error in a block-based twodimensional linear prediction of the image intensity. The median filter is subsequently applied to the pixels detected to be corrupted by the impulse noise. Simulation results show th...

Aktmcz-We present a fast algorithm for two-dimensional median fiitering. It is based on storing and updating the gray level histogram of the picture elements in the window. The algorithm is much faster than conventional sorting methods. For a window size of m X n, the computer time required is O(n).

Vector (multichannel) signal processing has arisen in the last decades as a major area of interest. The classical single-channel (scalar valued) processing techniques cannot deal with the interchannel dependencies, yielding to the development of new methods. This paper investigates two approaches to the median filtering of vector valued signals: filtering based on the reduced ordering in the sp...

This paper presents a review on digital image filtering techniques. The main emphasis is on median filtering and its extended versions like hybrid median filtering, relaxed median filtering etc. It is found that still median filtering demands some sort of enhancements as it is best for salt and pepper noise only. By conducting a survey suitable gaps are found in existing literature. In the end ...

The scalar median filter (SMF) is often used to reduce noise in scalar geophysical data. We present an extension of the SMF to a vector median filter (VMF) for suppressing noise contained in geophysical data represented by multidimensional, multicomponent vector fields. Although the SMF can be applied to each component of a vector field individually, the VMF is applied to all components simulta...

With the advent of the inexpensive CCD (Charge-Coupled Device) on a chip, the wide-spread move from traditional 35mm film photography to digital photography is becoming increasingly apparent especially with journalists and professional photographers. This has prompted digital camera manufacturers to try to implement most of the legacy techniques common among traditional film cameras such as hig...

The median filter is a special case of nonlinear filter used for smoothing signals. Since the output of the median filter is always one of the input samples, it is conceivable that certain signals could pass through the median filter unaltered. These signals, invariant to further passes of the median filter, define the signature of a filter and are referred to as root signals. This represents t...