This paper describes an unsupervised region merging technique based on a no
vel robust statistical test. The merging decision is derived from the mutua
l inlier ratio (MIR) of adjacent regions. This ratio is computed using robu
st regression techniques and a novel method to estimate the robust scale of
the Gaussian distribution. A discrimination value to recognize identical G
aussian distributions with the MIR is derived theoretically as a function o
f the sizes of the compared sets. The presented method to test distribution
s is compared with the established Kolmogorov-Smirnov test and implemented
into a segmentation algorithm for planar range images. The iterative region
growing technique is evaluated using an established framework for range im
age segmentation comparison involving 60 real range images. The evaluation
incorporates a comparison with four state-of-the-art algorithms and gives a
n experimental demonstration of the need for robust methods capable of hand
ling noisy data in real applications.