A method of compressing an image block comprising multiple image elements into a compressed block representation, said method comprises the steps of: assigning, for each color component of each image element of said image block, predefined color weights w x,y based on a position (x, y) of said image element in said image block; determining, based on said assigned predefined color weights w x,y and original colors of said multiple image elements, at least two color codewords (710, 720, 730, 740) that are representations of at least two color values, said compressed block representation comprising said at least two color codewords (710, 720, 730, 740); and representing said original colors of said multiple image elements by color representations that are derived from said at least two color values, wherein said color representations of said image elements are derived from linear combinations of said at least two color values weighted by said assigned predefined color weights w x, y, and wherein said color representation of said image element is obtained by multiplying each color component of said at least two color values by the corresponding assigned predefined color weight w x,y of said color component at said position (x, y) of said image element, characterized in that said color weights w x,y are predefined so that said color weights w x,y monotonically decrease along each row of image elements in said image block, or monotonically increase along each row of image elements in said image block; and said color weights w x,y are predefined so that said color weights w x,y monotonically decrease along each column of image elements in said image block, or monotonically increase along each column of image elements in said image block. assigning, for each color component of each image element of said image block, predefined color weights w x,y based on a position (x, y) of said image element in said image block; determining, based on said assigned predefined color weights w x,y and original colors of said multiple image elements, at least two color codewords (710, 720, 730, 740) that are representations of at least two color values, said compressed block representation comprising said at least two color codewords (710, 720, 730, 740); and representing said original colors of said multiple image elements by color representations that are derived from said at least two color values, wherein said color representations of said image elements are derived from linear combinations of said at least two color values weighted by said assigned predefined color weights w x, y, and wherein said color representation of said image element is obtained by multiplying each color component of said at least two color values by the corresponding assigned predefined color weight w x,y of said color component at said position (x, y) of said image element, characterized in that said color weights w x,y are predefined so that said color weights w x,y monotonically decrease along each row of image elements in said image block, or monotonically increase along each row of image elements in said image block; and said color weights w x,y are predefined so that said color weights w x,y monotonically decrease along each column of image elements in said image block, or monotonically increase along each column of image elements in said image block.