Susu Yao Ee Ping Ong Mei Hwan Loke Peceptual distortion metric based on wavelet frequency sensitivity and multiple visual fixations. 408-411 2008 ISCAS http://dx.doi.org/10.1109/ISCAS.2008.4541441 conf/iscas/2008 db/conf/iscas/iscas2008.html#YaoOL08