1. A method of spatially interpolating pixel values of an image, wherein first colour component pixel values of the image are spatially interpolated by making use of second colour component pixel values of the said image, the second colour component pixel values not being co-sited with the first colour component pixel values, comprising the steps of: spatially interpolating the second colour component pixel values so as to obtain, at least, second colour component pixel values co-sited with the first colour component pixel values; deriving an intermediate value from each interpolated second colour component pixel value and the respective co-sited first colour component pixel value; spatially interpolating the intermediate values to obtain interpolated intermediate values; and, combining the said interpolated intermediate values with the said second colour component pixel values or with second colour component pixel values derived therefrom to obtain spatially interpolated pixel values of the first colour component.