Abstract:In order to further reduce the computation in UMHexagonS algorithm, the paper first detailed studies UMHexagonS algorithm search processing, and studies motion direction prediction, and combines motion direction prediction with square search and unsymmetrical multi-hexagon search in UMHexagonS algorithm, an improved algorithm is proposed. The test and simulation by three different sequences are done. The test results show that the improved UMHexagonS algorithm can significantly decrease search points when the search accuracy and rate are similar.