| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the capacity of an image memory for storing a reference screen used for motion compensation prediction, to perform miniaturization, to reduce weight and to lower a cost in a decoder for decoding MPEG(moving picture experts group) 2. SOLUTION: A data compression circuit 7 for compressing the data amount of data stored in the image memory 8 is provided in the preceding stage of the image memory 8 used for the motion compensation prediction and a data expansion circuit 9 for returning compressed data read from the image memory to the original is provided in the poststage of the image memory 8. Thus, image data are compressed at the time of storing the data of the reference screen in the image memory used for the motion compensation prediction, the memory capacity of the image memory used for the motion compensation prediction is reduced, a circuit scale is reduced and the cost is reduced. At the time, since the image data are compressed independently with the block layer of DCT (discrete cosine transformation) as a unit, matching with a DCT block is performed and a successive processing is made possible.</p> |
