| 摘要 |
PURPOSE:To shorten the restoring processing time of a direct current block without the accuracy reduction of image data by performing the rounding processing of the output of a shifting means based on the lower order N bit information of a direct current component in a coefficient matrix obtained by a decoding means, and selecting and outputting it. CONSTITUTION:From code image data orthogonal-conversion-coded by a decoding means 101, an effective coefficient matrix is extracted, and image data are restored at a reverse orthogonal converting means 102. On the other hand, the direct current component in the coefficient matrix is N-bit-shifted to the right by a shifting means 111, the output of the means 111 in accordance with the lower order N-bit of the direct current component is rounding-processed by a rounding processing means 112, and becomes the direct current component restoring image of the same accuracy as the output of the means 102. Through a block detecting means 103 to detect the direct current component, a selecting means is controlled, and the restoring image of the means 102 or the means 112 is selected. By such a constitution, without the accuracy reduction of the image data, the restoring processing time of the direct current block is shortened. |
