Patent ID: 8897357

Claim:
An image encoding apparatus, the apparatus comprising: a coefficient calculator configured to calculate adaptive interpolation filter coefficients of a current frame; an image encoder configured to interpolate a reference frame with a fractional pixel precision by using the adaptive interpolation filter coefficients of the current frame, and encode the current frame by using the interpolated reference frame; a filter flag encoder configured to determine whether to interpolate the reference frame by using adaptive interpolation filter coefficients of a previous frame based on a comparison between the adaptive interpolation filter coefficients of the current frame and the adaptive interpolation filter coefficients of the previous frame, and encode a coefficient-inserted flag or a coefficient non-inserted flag as a filter flag into a bit stream based on the result of the determining; and a coefficient encoder configured to encode the adaptive interpolation filter coefficients of the current frame into the bit stream when the filter flag is the coefficient-inserted flag, and not encode the adaptive interpolation filter coefficients of the current frame into the bit stream when the filter flag is the coefficient non-inserted flag, wherein the coefficient non-inserted flag indicates that the adaptive interpolation filter coefficients of the previous frame are used as the adaptive interpolation filter coefficients of the current frame.