An image processing method converts an original image represented in an original color gamut to a target image represented in a target color gamut. The image processing method comprises: A) calculating a set of primary color direction deviations between a set of original primary color directions of the original color gamut and a set of target primary color directions of the target color gamut, wherein each of the set of primary color direction deviations corresponds to a primary color; B) determining, for each pixel in the original image, a corrected color coordinate of the pixel based on a set of offsets of an original color coordinate of the pixel in the original color gamut relative to the set of original primary color directions and the set of primary color direction deviations; and C) mapping, for each pixel in the original image, the corrected color coordinate of the pixel into the target color gamut to generate a target color coordinate of the pixel in the target color gamut.