| 摘要 |
<p>Quantization noise can be reduced so that a user can hardly perceive the noise and it is possible to prevent lowering of the frequency resolution and lowering of the coding efficiency. A signal coding apparatus includes a quantization unit (5) for performing quantization of an input signal according to a plurality of quantization methods, a de-quantization unit (6) for performing de-quantization so as to acquire a plurality of decoded signals, an error signal calculation unit (8) for calculating an error signal between a decoded signal and the input signal, a weighting calculation unit (2) for calculating for each division block the weight relating to the degree of perception of the quantization noise corresponding to the error signal by the user, a quantization method selection unit (12) for selecting a predetermined quantization method among a plurality of quantization methods according to the weighted error signal when a plurality of weighted error signals are generated indicating weighted signals of respective division blocks, and an output unit (16) for outputting as an output signal an input signal which has been quantized according to a predetermined quantization method.</p> |
