Motion Estimation Based on Mutual Information and Adaptive Multi-Scale Thresholding. 
This paper proposes a new method of calculating a matching metric for motion estimation.  The proposed method splits the information in the source images into multiple scale and orientation subbands, reduces the subband values to a binary representation via an adaptive thresholding algorithm, and uses mutual information to model the similarity of corresponding square windows in each image.  A moving window strategy is applied to recover a dense estimated motion field whose properties are explored.  The proposed matching metric is a sum of mutual information scores across space, scale, and orientation.  This facilitates the exploitation of information diversity in the source images.  Experimental comparisons are performed amongst several related approaches, revealing that the proposed matching metric is better able to exploit information diversity, generating more accurate motion fields.