1. Field of the Invention
This invention relates to a moving picture reproduction apparatus and a moving picture coding and decoding system which employs a moving picture reproduction apparatus.
2. Description of the Related Art
Conventionally, a moving picture is usually coded and decoded using motion compensation interframe prediction processing. As an example, in the coding and decoding system H.261 for a moving picture standardized by the ITU-T (International Telecommunication Union-Telecommunication Standardization Sector), an input picture is divided into blocks of 16 picture elements.times.16 lines and motion compensation interframe prediction is performed in units of one block using a reference picture. As the reference picture, a decoded picture obtained in the inside of a decoding apparatus by decoding coded picture data transmitted last thereto is used. Auxiliary information which has been used in the motion compensation interframe prediction and an error signal obtained in the prediction are coded and transmitted.
With the coding and decoding system described above, however, since auxiliary information used in motion compensation and a prediction error signal are transmitted to the decoder side, where the transmission capacity is small, coded picture data cannot be transmitted sufficiently. Consequently, there is a problem in that a decoded picture suffers from significant degradation in picture quality or the frame rate of the decoded picture exhibits significant degradation.
Meanwhile, according to a "picture communication system" disclosed in Japanese Patent Laid-Open Application No. Showa 62-068384, a component constituting an object such as the face or an arm is extracted from an input picture, and a difference between the thus extracted component and standard part data held in a data base in advance is coded into and transmitted as a characteristic parameter or parameters. On the decoder side, a plurality of standard part data are transformed with the characteristic parameter or parameters and combined to compose a reproduced picture.
With the "picture communication system", however, although it can be realized with a small transmission capacity since only extracted parameters are coded and transmitted, since standard part data prepared in advance are transformed to obtain a reproduced picture, it is disadvantageous in that a delicate characteristic of an input picture cannot be represented sufficiently and the reproduced picture gives an artificial and unnatural feeling.
Further, a "coding and decoding method and apparatus for a moving picture" has been proposed which can decode and reproduce a picture most similar to an input picture even where the transmission capacity is small. In the "coding and decoding method and apparatus for a moving picture", an input picture at present is analyzed and compared with a plurality of input pictures, which have been coded and decoded in the past, to determine whether the input picture should be coded. If it is determined that the input picture should not be coded, then selection information for selecting one of the compared input pictures in the past which resembles the input picture most is transmitted to the decoder side. On the decoder side, coded data of coded input pictures are decoded and displayed and are recorded and held in advance, and when the selection information is received, one of the thus held coded input pictures which corresponds to the received selection information is selectively decoded and displayed.
With the "coding and decoding method and apparatus for a moving picture", however, since an input picture is analyzed to extract a parameter or parameters representing a characteristic or characteristics of the input picture and the thus extracted parameter or parameters are compared with parameter information in the past held by the coder side, not only it is necessary for the coder side to hold parameters of all of images which have been coded in the past, but also the processing for searching out a parameter or parameters of most high fidelity is complicated. Further, this method is not compatible with interframe predictive difference coding apparatus which are used most widely at present.