Efficient Block Matching Motion Estimation Using Multilevel Intra- and Inter-Subblock Features Subblock-Based SATD

Block matching based motion estimation employs conventionally pixel-based sum of absolute differences (SAD) metric for distortion measure. Many fast matching mechanisms have been developed to lower the computational load for block matching, such as those exploiting block feature based or attribute-based SAD calculations. By examining a subblock-sum-based SAD measure, where the subblock-sums can be considered to be intra-subblock features, we propose both intra- and inter-subblock features based SAD measure for more effective block matching in terms of achieving better coding efficiency. Interestingly, the proposed feature based SAD measure can be interpreted as subblock-based sum of absolute Hadamard transformed differences (SATD). The new features can be constructed in a multilevel structure, which may provide a flexible and scalable means for a tradeoff between computation load and coding efficiency. Encoding results are shown to compare the proposed scheme against other relevant feature based SAD measures.