| 摘要 |
<p>PURPOSE:To prevent the generation of distortion by which the block boundary of a restored picture is conspicuous by utilizing either average value data or index information which is not erroneous and correcting the error of a noticed block lost by the error. CONSTITUTION:In the correction algorithm of an error correcting circuit 16, when one of an average value and index information is erroneous and the other is not erroneous, the information which is not erroneous is effectively utilized. That is, when the average value is erroneous, a tentative decoded picture element value is generated from an appropriate offset and a decoding differential value. Since correlation is intimate between the mutually adjacent picture elements of the pictures, the correlation between the tentative decoded picture element value and the correctly decoded picture elements value of a peripheral block is investigated and the offset maximizing the correlation is estimated as the average value. Also, when the index information is erroneous, the picture element value of the block under consideration is interpolated by using the correctly decoded picture element value of the peripheral block. An interpolated picture element value is corrected corresponding to a difference between the average value generated from the interpolated picture element value and the average value which is not erroneous.</p> |
