Image decoding device and image decoding method

An image decoding device method for obtaining image signals by decoding compressed data of digital moving image signals in a 4:4:4 format is disclosed. An identification signal is decoded, the identification signal indicating whether three color component signals have been encoded in a common encoding mode or in independent encoding modes. The common encoding mode corresponds to a process of encoding the three color component signals of one frame by a common macroblock type information and the independent encoding mode corresponds to a process of encoding the three color component signals of one frame by an individual independent macroblock type information. The three color component signals are decoded in a common encoding mode or in independent encoding modes according to the identification signal.