| 摘要 |
<p>PURPOSE:To easily reduce the data quantity of encoded code data through small processing quantity by entropy-decoding the encoded data, and generating a quantized orthogonal transformation coefficient, and making a part of a non-zero quantized orthogonal transformation coefficient zero. CONSTITUTION:The inputted code data is decoded by an entropy decoding part 10, and is restored into the quantized orthogonal transformation coefficient Sq. This quantized orthogonal transformation coefficient Sq is supplied to a coefficient value changing part 12, and a part of the non-zero coefficient is converted into a zero coefficient. Then, every time one quantized orthogonal transformation coefficient is decoded, a counter installed in a frequency calculating part 14 is counted up by one, and the value (u, v) of corresponding frequency is determined by referring to a table on the basis of the order of the quantized orthogonal transformation coefficient determined by that coefficient value, and if it is larger than spatial frequency Th, this quantized orthogonal transformation coefficient is changed into the zero coefficient. Further, the quantized orthogonal transformation coefficient in which a part of the coefficient was changed into the zero coefficient by the coefficient value changing part 12 is encoded again by an entropy encoding part 16.</p> |
