| 摘要 |
PROBLEM TO BE SOLVED: To reproduce music signals with high sound quality by expanding a frequency band.SOLUTION: A band pass filter 13 divides an input signal into a plurality of sub-band signals. A feature quantity calculation circuit 14 calculates feature quantity by using at least one of the plurality of sub-band signals and the input signal divided. A high range sub-band power estimation circuit 15 calculates an estimation value of high range sub-band power on the basis of the calculated feature quantity. A high range signal generation circuit 16 generates a high range signal component on the basis of the plurality of sub-band signals divided by the band pass filter 13 and the estimation value of the high range sub-band power calculated by the high range sub-band power estimation circuit 15. A frequency band expansion device 10 expands a frequency band of the input signal by using the high range signal component generated by the high range signal generation circuit 16. The invention can be applied to, for example, a frequency band expansion device, an encoder, a decoder, and the like. |
