A method and device for encoding an image into a scalable bitstream, the method including acts of dividing the Image in image blocks; encoding each image block in accordance with one of a plurality of different encoding modes, to obtain corresponding block bitstreams comprising one or more types of data representative of said encoding mode; and forming the scalable bitstream by iteratively scanning the block bitstreams, each scan including acts of: selecting at least one of said types of data, including in the scalable bitstream data of the selected types from the block bitstreams, and including in the scalable bitstream flags indicating the selected types of data.