Image A is an original sample taken from the HAUSGARTEN IV transect. B - F show the effect of different kernel sizes M for the Gaussian filter. The kernel sizes are as follows: B: M = 11, C: M = 101, D: M = 701, E: M = 1101, F: M = 1401). The curves show the output of the cluster-indices, plotted against M. The first value (M = 0) represents the unfiltered image. The curves are as follows: blue: Chalinski-Harabasz, green: Index-I, yellow: Davies-Boudlin, pink: intra-cluster variance, red: inter-cluster variance. The bold, black line is the mean of the five measures. The cluster indices were normalized to the interval [0.1] and show a good correlation, supporting a reasonable selection of the value M = 701.