A new method for affine invariants extraction based on affine geometry[J]. Journal of Image and Graphics, 2011, 16(3): 389-397. DOI: 10.11834/jig.20110315.
A new affine invariants based on affine geometry for object recognition and matching is proposed in the paper. The algorithm can be divided into three following steps. Firstly
extract the centroid and extend centroid of the object region. The connecting line between them thus devides the region into two parts
and the centroids of the two parts will be recalculated. Iteratively
we can obtain the demand centroids that satisfy the requirement. Secondly
calculate the areas of the quadrangles
whose vertexes are the centroids of the regions cut by the connecting line and the centroids of the two parts. Thirdly
calculated the ratios of the areas and the affine invariant vector is acquired Besides
the parameters of the affine transform can also be computed by the coordinates of the centroids. It is proved by the experiment that the extracted affine invariants are of robustness