| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an improved method for video compression. <P>SOLUTION: A video encoding apparatus includes: a transform section which performs integer transform on a prediction error to calculate an integer transform coefficient with a transform base (i, j) as an index; and a quantization section which quantizes a matrix of integer transform coefficients to calculate a matrix of quantization values. The matrix of the quantization values is calculated by multiplying the matrix of integer transform coefficients by a mantissa portion (Am(QP)[i][j]) of the quantization parameter and an exponent portion (2<SP>Ae(QP)[i][j]</SP>) of the quantization parameter. The mantissa portion is a function that is periodical in a period P (P is a constant) and the exponent portion has a structure, of Ae(QP)[i][j]=Ae-QP/P, consisting of the constant P and a constant Ae. A value of the quantization parameter becomes half in each period P. An image decoding apparatus performs inverse quantization, inverse integer transform on the matrix of quantized values and decodes the matrix. <P>COPYRIGHT: (C)2010,JPO&INPIT |
