1. A method for encoding at least one image represented by a sequence of symbols generated according to a predetermined encoding scan order, wherein the method comprises the following steps: determining sub-sequences in each sequence, a sub-sequence comprising a predetermined grouping of symbols; and scanning determined sub-sequences comprising the following sub steps for at least one current sub-sequence and for at least one context, wherein at least one step is performed by a processor device: determining a neighboring group comprising a least two previously encoded sub-sequences, called a current encoded neighboring group, amongst which at least one belongs to an encoded neighboring group associated with a sub-sequence, distinct from said current sub-sequence, said distinct sub-sequence not belonging to said encoded neighboring group of the current sub-sequence, and said current sub-sequence not belonging to the encoded neighboring group of said distinct sub-sequence; initializing at least one probability of appearance of a symbol associated with the context, called a current probability of appearance, taking account of at least two probabilities of appearance of said symbol, called known probabilities of appearance, relative to two previously encoded sub-sequences of said current encoded neighboring group; successive entropy encoding of said symbols according to said predetermined encoding scan order and, for each symbol, updating of said current probability of appearance for the context associated with said symbol; and storing said current probability of appearance of said encoded symbols in the current sub-sequence in a computer-readable memory, after encoding of the last symbol of said current sub-sequence.