Irene Epifanio Jaime Gutierrez Jesus Malo Linear transform for simultaneous diagonalization of covariance and perceptual metric matrix in image coding. 1799-1811 2003 36 Pattern Recognition 8 http://dx.doi.org/10.1016/S0031-3203(02)00325-4 db/journals/pr/pr36.html#EpifanioGM03