Title :
Image sequence enhancement based on adaptive symmetric order statistics
Author :
Ko, Sung-Jea ; Forest, Thomas M.
Author_Institution :
Dept. of Electron. Eng., Korea Univ., Seoul, South Korea
fDate :
8/1/1993 12:00:00 AM
Abstract :
Statistical properties of the spatiotemporal center-weighted median (CWM) filter for image sequences are investigated. It is statistically shown that the CWM filter preserves image structures under motion at the expense of noise suppression. To improve the CWM filter so it can be effectively used in image sequence processing, the adaptive directional CWM filter (ADCWM) is proposed. This filter utilizes a multistage filtering structure, based on adaptive symmetric order statistic (ASOS) operators which produce a pair of order statistics symmetric about the median. The ASOSs are selected by using adaptive parameters adjusted by local image statistics. It is shown experimentally that the proposed filter can preserve image structures while attenuating noise without the use of motion estimation
Keywords :
adaptive filters; filtering and prediction theory; image sequences; statistical analysis; adaptive directional CWM filter; adaptive parameters; adaptive symmetric order statistics; image sequence processing; local image statistics; median filter; multistage filtering structure; sequence enhancement; spatiotemporal center-weighted; Adaptive filters; Filtering; HDTV; Image sequences; Motion estimation; Noise reduction; Nonlinear distortion; Nonlinear filters; Spatiotemporal phenomena; Statistics;
Journal_Title :
Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on