Positioning control of UAV is one of the research areas of autonomous navigation. Regional feature matching algorithm
is commonly used in the positioning control of UAVs. This paper proposes a regional feature matching algorithm, in
which edges and gray-levels within image regions are extracted. The correspondences between regional features are then
obtained in terms of invariant moments and chain-code representation of regions. The transformation parameters are
estimated based on the centers of gravity of regions. Experimental results show the effectiveness of the proposed
algorithm using salient regional features.