A method for decoding a stream having first and second portions portion and representing an image divided into blocks. The method includes a sequence test having a predetermined non-zero number of bits, including two at the power of the predetermined number (2N) iterations of the following substeps, for a current block: obtaining a sequence distinct from sequences already tested; decoding and reconstructing a version of the current block from the obtained sequence and from coded data in the first portion; evaluating a likelihood measurement associated with the reconstructed block; decoding information characteristic of a first sequence including the predetermined number of binary symbols from the second portion; selecting a sequence from the sequences tested, based on the likelihood measurements and the decoded information, the selected sequence being identified as the first sequence; and decoding and reconstructing the current block from the first sequence and the first portion.