There is disclosed an encoder, a decoder, related methods, and non-transitory storage units storing instructions which, when executed by a computer, cause the computer to perform the methods.
At an encoder (300), after a spatial transformation stage (304), there is obtained a spatially transformed version (306) of input image information (302) having multiple bands and, for each band, multiple transform band coefficients. After the generation of precincts (311), each comprising transform coefficients covering a predetermined spatial area of the input image information (302), there is provided a component transformation stage (320, 325), to apply one component transformation (CTr) selected (327) out of a plurality of predetermined component transformations, to each band (102′) of each precinct (311). Hence, there is obtained a spatially transformed and color transformed version (323) of the input image information (302), which is subsequently quantized and entropy encoded.