

n N  Specifies how many times (N) the smoothing operation is applied to the image. The default value is N=1. 
w N 
The weight factor for the central pixel in each 3x3 mask.
The default value is N=1.
If p N and w 0, the processing is identical to the knearest neighbor smoothing with k=N1. See references for the details of the method. 
p N 
Specifies the number of the using pixels including the central pixel.
The default value is N=3, i.e., 2 pixels nearest in color (graylevel)
affect the new color of the central pixel.
If the input image is noisy, p 4 or p 5 will be helpful. If p 9 and w 1, the processing is identical to calculating the moving average with a 3x3 mask. If p 1, lpsmooth does nothing except consuming some memory and enormous CPU power. 
verbose 
Show processing information.

Even if p 3, line segments may get shorter by at most 2 pixels, because the two pixels on the edges of a line segment are blurred slightly.For the color image processing, the color similarity is measured by the Euclidian distance in RGB color space.
pgm(5), ppm(5)
L.S. Davis and A. Rosenfeld, "Noise Cleaning by Iterated Local Averaging," IEEE Trans. SMC, vol.SMC8, No.9, pp.705710, 1978.
Copyright (C) 20002002 Hideaki GotoEMail: hgot@rd.isc.tohoku.ac.jp, hgot@aso.ecei.tohoku.ac.jp
>  LPSMOOTH (1)  Feb 2002 
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