| 摘要 |
PURPOSE:To realize high encoding efficiency in spite of the state of an image, by selecting an orthogonal transform data of minimum differential quantity by an arithmetic means, and coding the differential signal. CONSTITUTION:By taking a difference between the orthogonal transform data and plural data by differentiators 103-106, and selecting the data with the highest efficiency by a selector 108 based on prescribed reference, coding as a differential data is applied. In other words, plural data are the orthogonal transform data of the same block of all of the frames, the orthogonal transform data of the partial block of a present frame, the orthogonal transform data of a background image consisting of a temporally integrated background image or an image block at a specific time, and the orthogonal transform data at the specific time. Thus, by using the orthogonal transform data consisting of the temporally integrated background image or the image block at the specific time, the differential data goes to a very small value when a certain image part is returned to its original position in the reciprocal movement of the certain image part, then, it is possible to improve the coding efficiency more remarkably than the orthogonal transform data at the same position of all of the frames. |
