Multi-stage Directional Median Filter

Median filter is widely used to remove impulse noise without blurring sharp edges. However, when noise level increased, or with thin edges, median filter may work poorly. This paper proposes a new filter, which will detect edges along four possible directions, and then replace noise corrupted pixel with estimated noise-free edge median value. Simulations show that the proposed multi-stage directional median filter can provide excellent performance of suppressing impulse noise in all situations.

Authors:

• Zong Chen
• Li Zhang

Keywords:

• Impulse noise
• Median filter
• Multi-stage
• Edgepreserving

References:

[1] W. K. Pratt, Digital Image Processing, John Wiley & Sons, 1978.
[2] T. Sun and Y. Neuvo, "Detail-preserving median based filters in image
processing," Pattern Recognition Letters, vol. 15, no. 4, pp. 341-347,
1994.
[3] D. A. Florencio and R. W. Schafer, "Decision-based median filter using
local signal statistics," in Proceedings of SPIE Symposium, Visual
Communication Image Processing, vol. 2038. pp. 268-275.
[4] Z. Wang and D. Zhang, "Progressive switching median filter for the
removal of impulse noise from highly corrupted images," IEEE
Transactions on Circuits System II, vol. 46, no. 1, pp. 78-80, 1999.
[5] S. Zhang and M. A. Karim, "A new impulse detector for switching
median filters," IEEE Signal Processing Letters, vol. 9, no. 4, pp. 360-
363, 2002.
[6] H. Hwang and R. A. Haddad, "Adaptive median filters: new algorithms
and results," IEEE Transactions on Image Processing, vol. 4, no. 4, pp.
499-502, 1995.
[7] C. Bouman and K. Sauer, "On discontinuity-adaptive smoothness priors
in computer vision," IEEE Transactions on Pattern Analysis and
Machine Intelligence, vol. 17, pp. 576-586, 1995.
[8] T. F. Chan, H. M. Zhou, and R. H. Chan, "A continuation method for
total variation denoising problems," Proceedings of SPIE Symposium on
Advanced Signal Processing: Algorithms, Architectures, and
Implementations, ed. F. T. Luk, pp. 314-325, 1995.
[9] P. Charbonnier, L. Blanc-F'eraud, G. Aubert, and M. Barlaud,
"Deterministic edge-preserving regularization in computed imaging,"
IEEE Transactions on Image Processing, vol. 6, pp. 298-311, 1997.
[10] C. R. Vogel and M. E. Oman, "Fast, robust total variation-based
reconstruction of noisy, blurred images," IEEE Transactions on Image
Processing, vol. 7, pp. 813-824, 1998.
[11] R. H. Chan, C. Ho, and M. Nikolova, "Salt-and-Pepper Noise Removal
by Median-type Noise Detectors and Edge-preserving Regularization,"
IEEE Transactions on Image Processing, vol. 14, pp. 1479-1485, 2005.
[12] Y. Dong and S. Xu. "A New Directional Weighted Median Filter for
Removal of Random-Valued Impulse Noise," IEEE Signal Processing
Letters, vol. 14, no. 3, pp. 193 - 196, 2007.