1. An image decoding method with a processor, the method comprising: receiving a first image; receiving metadata comprising prediction parameters for a multi-channel multiple-regression (MMR) prediction model, wherein the MMR model is adapted to predict a second image in terms of the first image; and applying the first image and the prediction parameters to the MMR prediction model to generate an output image approximating the second image, wherein pixel values of at least one color component of the output image are computed based on pixel values of at least two color components in the first image, wherein the MMR model comprises a first order MMR model with cross products according to the formula: 
 {circumflex over (v)} i =sc i {tilde over (C)} (1) +s i {tilde over (M)} (1) +n, wherein {circumflex over (v)} i [{circumflex over (v)} i1 {circumflex over (v)} i2 {circumflex over (v)} i3 ] denotes the predicted three color components of the i-th pixel of the output image, s i =[s i1 s i2 s i3 ] denotes the three color components of the i-th pixel of the first image, {tilde over (M)} (1) is a 3×3 prediction parameter matrix and n is a 1×3 prediction parameter vector according to M ~ ( 1 ) = [ m 11 ( 1 ) m 12 ( 1 ) m 13 ( 1 ) m 21 ( 1 ) m 22 ( 1 ) m 23 ( 1 ) m 31 ( 1 ) m 32 ( 1 ) m 33 ( 1 ) ] , and n = [ n 11 n 12 n 13 ] , {tilde over (C)} (1) is a 4×3 prediction parameter matrix according to C ~ ( 1 ) = [ mc 11 ( 1 ) mc 12 ( 1 ) mc 13 ( 1 ) mc 21 ( 1 ) mc 22 ( 1 ) mc 23 ( 1 ) mc 31 ( 1 ) mc 32 ( 1 ) mc 33 ( 1 ) mc 41 ( 1 ) mc 42 ( 1 ) mc 43 ( 1 ) ] , and sc i is a 1×4 vector according to sc i [s i1 ·s i2 s i1 ·s i3 s i2 ·s i3 s i1 ·s i2 ·s i3 ].