References
，
Standard Median: A. Bovik, Handbook of Image and Video Processing,
Academic Press, 2000.
，
Progressive switching median: Z. Wang and D. Zhang, "Progressive switching
median filter for the removal of impulse noise from highly corrupted images,"
IEEE Transactions on Circuits and Systems II, 46 (1999), pp. 78-80.
，
Multi-state median: T. Chen and H. R. Wu, "Space variant median
filters for the restoration of impulse noise corrupted images," IEEE Transactions
on Circuits and Systems II, 48 (2001), pp. 784-789.
，
Directional difference-based switching median: Y. Hashimoto, Y. Kajikawa
and Y. Nomura, "Directional difference-based switching median filters,"
Electronics and Communications in Japan, 85 (2002), pp. 22-32.
，
Noise adaptive soft-switching median: H.-L. Eng and K.-K. Ma, "Noise adaptive
soft-switching median filter," IEEE Transactions on Image Processing,
10 (2001), pp. 242-251.
，
Improved switching median: S. Zhang and M. A. Karim, "A new impulse
detector for switching median filters," IEEE Signal Processing Letters,
9 (2002), pp. 360-363.
，
Adaptive median: H. Hwang and R. A. Haddad, "Adaptive median filters: new algorithms
and results," IEEE Transactions on ImageProcessing, 4 (1995), pp.
499-502.
，
Variational method: M. Nikolova, "A variational approach to remove
outliers and impulse noise," Journal of Mathematical Imaging and Vision,
20 (2004), pp. 99-120.
，
Our proposed algorithm:
R. Chan, C.W. Ho, and M. Nikolova, "Salt-and-pepper
noise removal by median-type noise detector and
edge-preserving regularization." Accepted for publication
by IEEE Transactions on Image Processing.