Abstract:

Image registration based on key-point mappings usually provides alignment of integer-pixel precision. Sub-pixel registration is of great challenge to the technique exploiting key-point mappings. The authors proposed an interactive algorithm to address the sub-pixel registration problem. The proposed algorithm comprises two steps,the first step is to input control points and is getting a rough registration by using projection transform and linear least square algorithm, the second step is to adjust the control points with sub-pixel step. The average distance of control points was applied to quantitatively measure registration quality. The evaluation method combined with subjective and objective judgment was used. Experiment shows that the proposed algorithm can achieve sub-pixel registration result. The performance will be more reliable than other registration technique using scale invariant feature transform and partial intensity invariant feature descriptor, and also the performance of multimodal image registration gets significantly improved.

Key words: alignment, sub-pixel, control points, multimodal