1. Laboratory of Technologies and Applied Sciences, University of Douala, Douala, Cameroon
2. Signal, Image and Systems Laboratory, Higher Technical Teacher Training College of Ebolowa, University of Yaounde 1, Yaoundé, Cameroon
3. Laboratory of Electrical Engineering, Mechatronic and Signal Treatment, National Advanced School of Engineering, University of Yaounde 1, Yaoundé, Cameroon
4. School of Geology and Mining Engineering, University of Ngaoundéré, Ngaoundéré, Cameroon
5. College of Physics and Information Engineering, Fuzhou University, Fuzhou, China