Title :
Center weighted median filters and their applications to image enhancement
Author :
Ko, Sung-Jea ; Lee, Yong Hoon
Author_Institution :
Dept. of Electr. & Comput. Eng., Michigan Univ., Dearborn, MI, USA
fDate :
9/1/1991 12:00:00 AM
Abstract :
The center weighted median (CWM) filter, which is a weighted median filter giving more weight only to the central value of each window, is studied. This filter can preserve image details while suppressing additive white and/or impulsive-type noise. The statistical properties of the CWM filter are analyzed. It is shown that the CWM filter can outperform the median filter. Some relationships between CWM and other median-type filters, such as the Winsorizing smoother and the multistage median filter, are derived. In an attempt to improve the performance of CWM filters, an adaptive CWM (ACWM) filter having a space varying central weight is proposed. It is shown that the ACWM filter is an excellent detail preserving smoother that can suppress signal-dependent noise as well as signal-independent noise
Keywords :
adaptive filters; filtering and prediction theory; interference suppression; picture processing; statistical analysis; additive white noise; center weighted median; detail preserving smoother; image enhancement; impulsive-type noise; median filters; noise suppression; signal-dependent noise; signal-independent noise; space varying central weight; statistical properties; Adaptive filters; Additive noise; Additive white noise; Character recognition; Degradation; Filtering; Image enhancement; Image recognition; Noise reduction; Smoothing methods;
Journal_Title :
Circuits and Systems, IEEE Transactions on
