Zusammenfassung
By convention, the translation and scale invariant functions of Legendre
moments are achieved by using a combination of the corresponding
invariants of geometric moments. They can also be accomplished by
normalizing the translated and/or scaled images using complex or
geometric moments. However, the derivation of these functions is
not based on Legendre polynomials. This is mainly due to the fact
that it is difficult to extract a common displacement or scale factor
from Legendre polynomials. In this paper, we introduce a new set
of translation and scale invariants of Legendre moments based on
Legendre polynomials. The descriptors remain unchanged for translated,
elongated, contracted and reflected non-symmetrical as well as symmetrical
images. The problems associated with the vanishing of odd-order Legendre
moments of symmetrical images are resolved. The performance of the
proposed descriptors is experimentally confirmed using a set of binary
English, Chinese and Latin characters. In addition to this, a comparison
of computational speed between the proposed descriptors and the aforesaid
geometric moments-based method is also presented.
Nutzer