To eliminate adverse effects of the increase in the amount of arithmetic operations for motion compensation of an image decoding signal on the quality of a reproduced image by preventing the amount of arithmetic operations from exceeding the arithmetic processing capability of a system due to motion compensation of the image decoding signal.

An image processing unit is provided with a prediction signal generating section 210 that predicts an image decoding signal of an object block for decoding by a prescribed method and with a load discrimination device 213 that detects the amount of arithmetic operations in decoding a received image coding signal and selects a prediction method in generating the prediction signal depending on the above detected amount of arithmetic operations.