Efficient descriptor-filtering Algorithm for speeded up robust features matching

This paper presents an efficient descriptor filtering algorithm for the feature matching process of SURF. The matching algorithm used in OpenSURF compares each and every feature descriptors by calculating the root-mean-square error of the descriptor vectors. The proposed instant-termination and Bloom filtering algorithm pre-compares the feature descriptors and decides whether the compared descriptor pairs should be further inspected. The proposed pre-comparison process compares the most significant bits of the descriptor for early decision. Also, the descriptor bits are interleaved to adapt to the Bloom filter, increasing the reliability of the filtering process. Our proposed filtering algorithm effectively reduces the number of root-mean-square error calculations.