A self-adjusting weighted median filter for removing impulse noise in images

An intelligent self-adjusting weighted median filter for removing impulsive noise in images is presented. Three main techniques are developed to implement this self-adjusting weighted median filter: an intelligent classification to divide the image data into the "corrupted" pixels and the "uncorrupted" pixels, an efficient algorithm to find the median output of any weight set, and a realistic training procedure without the noise free image to obtain the proper weights. Our simulations on some test images demonstrate that the proposed filter has less smoothing effect and smaller mean square error (MSE) or mean absolute error (MAE) measurement than the standard median filter. At the same time, the quality of the filter output has been enhanced significantly. Finally, a demonstration chip of this weighted median filter for the 5/spl times/5 window size is also presented.

[1]  K. Chen.  Bit-serial realizations of a class of nonlinear filters based on positive Boolean functions , 1989 .

[2]  Jaakko Astola,et al.  Analysis of the properties of median and weighted median filters using threshold logic and stack filter representation , 1991, IEEE Trans. Signal Process..

[3]  Sung-Jea Ko,et al.  Center weighted median filters and their applications to image enhancement , 1991 .

[4]  Liangchien Lin,et al.  Input compression and efficient VLSI architectures for rank order and stack filters , 1994, Signal Process..

[5]  Byeongjang Jeong,et al.  Design of weighted order statistic filters using the perceptron algorithm , 1993, IEEE Winter Workshop on Nonlinear Digital Signal Processing.

[6]  D. R. K. Brownrigg,et al.  The weighted median filter , 1984, CACM.

[7]  Yrjö Neuvo,et al.  Fast adaptation and performance characteristics of FIR-WOS hybrid filters , 1994, IEEE Trans. Signal Process..

[8]  Kenneth E. Barner,et al.  Rank conditioned rank selection filters for signal restoration , 1994, IEEE Trans. Image Process..

[9]  Dhiraj K. Pradhan,et al.  A New Algorithm For Order Statistic , 1992, Workshop on VLSI Signal Processing.

[10]  Edward J. Coyle,et al.  Stack filters , 1986, IEEE Trans. Acoust. Speech Signal Process..

[11]  Liang-Gee Chen,et al.  A hardware-oriented design for weighted median filters , 1995, Proceedings of ASP-DAC'95/CHDL'95/VLSI'95 with EDA Technofair.

[12]  Liang-Gee Chen,et al.  Design and VLSI implementation of real-time weighted median filters , 1994, Proceedings of APCCAS'94 - 1994 Asia Pacific Conference on Circuits and Systems.

[13]  Jaakko Astola,et al.  Adaptive multistage weighted order statistic filters based on the backpropagation algorithm , 1994, IEEE Trans. Signal Process..