Hb. Mitchell, FAST SMALL-KERNEL K-NEAREST NEIGHBOR NOISE-SMOOTHING ALGORITHM, European transactions on telecommunications and related technologies, 6(5), 1995, pp. 609-612
A basic operation in image processing is the removal of noise from a n
oise-corrupted input picture. The K-nearest neighbour (KNN) is a very
effective noise-smoothing filter: it removes both additive and multipl
icative noise without blurring the edges and lines in the input pictur
e. The main drawback to this filter is its high computational complexi
ty. In this paper, the author describes a fast algorithm specifically
designed for the small-kernel KNN filter. The computational complexity
of the new algorithm is sufficiently low to facilitate real-time nois
e-smoothing.