An image representation format for representing a digital image comprises: image information stored as a bitstream representing sequential image blocks, each block comprising one or more components, each component comprising one or more data units and each data unit being represented as a Huffman-coded stream of coefficients of basis functions, wherein a zeroth order coefficient is represented as a difference to the previous zeroth order coefficient of the corresponding component, and a block information table, which comprises: indicators to the first coefficient of a specified order of each image block in said bitstream, information indicating the number of bits in the bitstream between adjacent coefficients of said specified order of the image block, and the zeroth order coefficient of at least the first data unit of each component, said zeroth order coefficient being represented in a non-differential form.