Fast block-based true motion estimation using distance dependent thresholds

A fast motion estimation algorithm, called distance-dependent thresholding search (DTS), is presented for block-based true motion estimation applications, and introduces the novel concept of variable distance dependent thresholds. The performance of the DTS algorithm is analysed and quantitatively compared with both the traditional and exhaustive full-search (FS) technique, and the computationally faster, non-exhaustive three-step-search (TSS) algorithm. Experimental results show that by applying an appropriate threshold function, the DTS algorithm not only matches the speed of the TSS algorithm, but both retains a block distortion error comparable to the global minimum produced by the FS algorithm, and avoids the problem of identifying a large number of spurious motion vectors in the search process.