IMAGE ENCODING DEVICE, IMAGE DECODING DEVICE, IMAGE ENCODING METHOD AND IMAGE DECODING METHOD
An encoding device includes a color component separating unit for separating an input bit stream for the respective color components, a block dividing unit for dividing an input color component signal into blocks to generate a signal of an encoding unit area, a predicted image generating unit for generating a predicted image for the signal, a determining unit for determining a prediction mode used for encoding according to a prediction efficiency of the predicted image, a prediction error encoding unit for encoding a difference between the predicted image corresponding to the prediction mode determined by the determining unit and the input color component signal, and an encoding unit for variable length-coding the prediction mode, an output from the prediction error encoding unit, and a color component identification flag indicating the color component to which the input bit stream belongs as a result of the color component separation.
1 . An image decoding device for receiving a bit stream obtained by compression-encoding a color moving image signal composed of a plurality of color components as an input and using motion compensation prediction decoding for each of the plurality of color components of the color moving image signal to decode the color moving image signal, comprising:
a color component identifying unit for decoding a color component identification flag for identifying the color component to which the input bit stream belongs to determine the color component whose encoded information is contained in the bit stream;
a decoding unit for decoding, from the bit stream, virtual pixel accuracy indication information indicating an upper accuracy limit of a virtual pixel used for generating a predicted image for each color component determined by the color component identifying unit and decoding information obtained by encoding a motion compensation prediction mode indicating a motion compensation prediction image generating method used for encoding an encoding unit area, a corresponding motion vector, and a prediction error from the bit stream according to a predetermined syntax for each encoding unit area;
a predicted image generating unit for generating a predicted image for a signal of the encoding unit area based on the virtual pixel accuracy indication information, the motion compensation prediction mode, and the motion vector;
a prediction error decoding unit for decoding a prediction error signal based on the information obtained by encoding the prediction error for the encoding unit area; and
an adder unit for adding an output from the predicted image generating unit and an output from the prediction error decoding unit,
wherein the decoding unit performs a decoding process of the motion vector based on the virtual pixel accuracy indication information.