A method for decoding a stream of coded data representative of a sequence of images is disclosed. The decoding method comprisesdetermining a prediction block,calculating the average of said prediction block,reconstructing, from said stream, a DC coefficient and AC coefficients relating to said current block,calculating an average of said current block from said average of said prediction block and said DC coefficient,calculating a weighted prediction parameter as being the ratio of the average of said current block and the average of said prediction block,transforming a block of coefficients comprising a null value as DC coefficient and said reconstructed AC coefficients into a residual block,reconstructing the current block by merging said residual block and said prediction block weighted by said weighted prediction parameter.A method for coding is further disclosed.