| 摘要 |
<p>PURPOSE:To decide a proper quantization map and to reduce deterioration in picture quality when a sample point is less by obtaining a function between a code quantity and a scale so as to decide the scale. CONSTITUTION:A picture data subject to discrete cosine transformation(DCT) by a DCT device 12 is quantized by using a quantization map to measure the quantity of a code quantity. A function of the code quantity and a scale is sampled exponentially and a function between the code quantity at a prediction point between sample points and the scale and a function of the code quantity by linear interpolation from the sample point and the scale are obtained to decide a scale SC. The picture data subject to DCT is quantized by using a new quantization map based on the scale SC decided in this way.</p> |
