A multi-parameter fusion algorithm (MPFA) for auto-focus (AF) is discussed. The image sharpness evaluation algorithm (ISEA) and zoom tracking method (ZTM) are combined for AF. The zoom motor position (z) and background complexity (c) are regarded as the main parameters of this algorithm. A priority table depending on z and c is proposed. Modified ISEA or ZTM is adopted according to the priority table value. The hardware implementation of the MPFA on Texas Instruments' Davinci digital signal processor is also provided. Results show that the proposed scheme provides faster focusing compared with the conventional approaches.