1. A method of processing components of an image for coding of an image portion of the image, the image being composed of at least a first component and a second component different to the first component, wherein samples of the second component are predictable from samples of the first component using a prediction model linking the first component to the second component, the prediction model having at least one model parameter value representing the link between samples of the second component and corresponding samples of the first component; the method comprising: determining a plurality of subsets of samples, each subset of samples being usable for computing said at least one model parameter value, wherein each subset of samples comprises samples selected from samples of neighbouring borders of the first component and the corresponding second component of the image portion to be encoded, according to at least one predetermined sampling pattern and corresponding predetermined shifting offset for shifting the respective predetermined sampling pattern along the respective neighbouring border; selecting, based on predetermined criteria, a subset of samples from among the plurality of subsets of samples; and predicting samples of the image portion to be encoded using the prediction model and the at least one model parameter determined from the selected subset of samples.