Patent ID: 8824825

Claim:
A transmission system comprising: a decoding device as a receiving device, the decoding device outputs an output signal by receiving, as an input, an 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, and the output signal being indicative of the contents, the decoding device including, a decoder configured to decoding the encoded signal, to generate a decoded signal, an up sampler configured to up-convert the decoded signal, a low-frequency component removing filter configured to generate a low-frequency-free signal by removing, a low-frequency component including at least a direct current component from the up-converted decoded signal, a nonlinear processor 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 based on the low-frequency-free signal when values of the low-frequency-free signal are at least in the vicinity of 0, and an adder configured to add the nonlinear process signal to the up-converted decoded signal, to generate an addition signal, the addition signal being the output signal, the contents are constituted of a plurality of frames that are consecutive in terms of time, the encoded signal includes, in each frame, any one of a first signal or a second signal, the first signal being a signal in which the original signal is encoded and the second signal being a signal in which a part of frequency components included in the original signal is encoded, and the decoder is configured to further (i) generate, as the decoded signal when the first signal is decoded, the decoded first signal, and (ii) generate the decoded signal by adding (a) a signal of a subsequent decoded signal generated immediately before that has been subjected to motion compensation with use of motion vector information calculated in the encoding, the motion vector information being used for carrying out inter-frame motion compensation prediction, to (b) a signal in which the second signal is decoded, when the second signal is decoded; and an encoding device as a sending device, the encoding device including (i) a frequency component extracting filter 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 (ii) an encoder configured to (a) 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 (b) make the signal thus encoded be included in the encoded signal.