Next, a coefficient of the loop filter and the loop filter application information are coded.

A filter coefficient update unit (4) updates a coefficient of the control signal filter (2) on the basis of the sound source signal and an error signal.

A filter coefficient update unit (4) updates a coefficient of the control signal filter (2) on the basis of the sound source signal and an error signal.

The adaptive filter (130) updates the filter coefficient gk(n) of the filter coefficient order (n) to be updated, using a decoding (L) signal and a decoding error(R) signal.

Filter coefficient calculating means (13) calculates the filter coefficient of the long-time prediction synthetic filter (12).

According to the update amount, a coefficient of the adaptive filter is updated.

In the present context, a zero-filled filter pertains to a filter which may be based on an LP-filter which is expanded with a number of zero-value filter coefficients between each coefficient in the original filter.

The adaptive filter coefficient updates can thereby be computed much faster, and the adaptive filter coefficients can be copied much faster from one filter to the other.

A first calculation unit calculates a first weighted sum by multiplying each pixel value of the input image in the center region C including the target pixel within the filter range, by the filter coefficient.

A second calculation unit calculates a second weighted sum by multiplying each pixel value of the input image in the peripheral region excluding the center region C within the filter range, by the filter coefficient.

In the first adaptive algorithm, a FIR filter coefficient vector Hnmj+1 at time j + 1 from the n-th input channel to the m-th output channel is created by adding an update vector to the coefficient vector Hnmj at time j.

This can eliminate a multiplier conventionally required for multiplying the filter coefficient for each tap output of the tap-equipped delay line.

A coefficient of the filter is decided so that the feed-forward controller (6) itself becomes an inverse system by the inputted instruction P and the position error ε.

The echo canceller further includes offset removal means for removing an offset component attributed to the affect of the low-range frequency from the filter coefficient of the adaptive filter.