Patent ID: 8811765

Claim:
An encoding device configured to output an encoded signal, the encoded signal including a signal in which an original signal is encoded, the original signal being indicative of contents of at least one of image and audio, the encoding device comprising: a frequency component extracting section configured to extract, from the original signal, a part of frequency components included in the original signal, to generate a frequency component extraction signal; and an encoding section configured to encode the frequency component extraction signal and the original signal in such a manner that the encoding is carried out while switching over between the frequency component extraction signal and the original signal, and making the signal thus encoded be included in the encoded signal, wherein the frequency component extracting section includes, a high-frequency component removing section configured to remove a high-frequency component from frequency components of the original signal, to generate a high-frequency-free signal, a high-frequency component generation section configured to generate harmonics of the high-frequency-free signal, and a subtraction section configured to subtract the harmonics of the high-frequency-free signal from the original signal, to generate the frequency component extraction signal, the high-frequency component generation section includes, a low-frequency component removing section configured to remove, from frequency components of the high-frequency-free signal, a low-frequency component at least including a direct current component, to generate a low-frequency-free signal, a nonlinear process section configured to generate a nonlinear process signal (i) in which positive and negative signs of the low-frequency-free signal are retained and (ii) which monotonically increases nonlinearly with respect to the low-frequency-free signal when values of the low-frequency-free signal are at least in the vicinity of 0, and an addition section configured to add the nonlinear process signal to the high-frequency-free signal, to generate the harmonics.