An encoding device and method are provided for encoding at least one image split into partitions. The method implements, for a current partition to be encoded, steps of: selecting at least one causal partition already encoded and then decoded; calculating at least one optimal encoding parameter associated with the selected causal partition, according to a predetermined criterion of encoding performance, by comparing a plurality of encoding parameters applied to the selected causal partition; and encoding the current partition by using the calculated optimum encoding parameter.