Noise and intensity invariant moments

Abstract Moments and moment invariants can be normalized such that they become completely insensitive to the absolute intensity of the studied image. When this normalization is applied, moments as well as moment invariants become highly insensitive to noise. This will be shown by computer simulations of noisy bi-level images. Up to high levels of noise the normalized invariants of noisy silhouettes hardly differ from those of perfect silhouttes. The distribution of invariants for a given noise level can be calculated by computer simulations and can be used to further improve the recognition algorithm.