The present invention relates to a method for scaling a first channel, wherein the method comprises computing a low resolution second channel based on a transformation of the second channel with a transformation function used to transform high resolution channel into a low resolution channel; computing a correlation function between the low resolution second channel and the first channel; determining a predicted second channel having the high resolution from the low resolution second channel according to a prediction method; computing an high-pass second channel based on the difference between the second channel and the predicted second channel and based on the correlation function; determining a predicted first channel having the high resolution from the first channel according to the prediction method.