A method of encoding a digitised image including several pixel lines, which consists in encoding one line with a series of sub-codes characteristic of the length of the successive fields and their colour. When the image includes several identical successive lines, the method encodes the first one of the successive lines and completes with a sub-code characterising the repetition of the line and the number of times the line is repeated following the first line. When the image includes several lines including the same succession of colours, the method encodes the first one of the several lines including the same successive code and completes the code with a succession of sub-codes characterising the repetition of the succession of colours and the length of different fields of the different lines.