1. Department of Electronics Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan
2. Department of Electronics Engineering and Computer Science, Tung Fang Design Institute, Kaohsiung 829, Taiwan
3. Department of Animation and Multimedia Design, Tung Fang Design Institute, Kaohsiung 829, Taiwan
4. Department of Electronics Engineering, Cheng-Shiu University, Kaohsiung 833, Taiwan