Arifin, A. Z., Heddyanna, A. F. F. and Studiawan, H. (2010) “Ultrafuzziness Optimization Based on Type II Fuzzy Sets for Image Thresholding”, Journal of ICT Research and Applications, 4(2), pp. 79-94. doi: 10.5614/itbj.ict.2010.4.2.2.