Method for image interpolation using asymmetric interpolation filter and apparatus therefor

An apparatus for motion compensation, the apparatus comprising:

• a luma interpolation filtering unit which is configured for determining, in a luma reference picture, a luma reference block for prediction of a current block, by using a luma motion vector of the current block, and generating a luma sample of ¼-pixel location or ¾-pixel location included in the luma reference block by applying a 7-tap filter to luma samples of an integer pixel location of the luma reference picture;
• and
• a chroma interpolation filtering unit which is configured for determining, in a chroma reference picture, a chroma reference block for prediction of the current block, by using a chroma motion vector of the current block, and generating a chroma sample of ⅛-pixel location or 4/8-pixel location included in the chroma reference block by applying a 4-tap filter to chroma samples of an integer pixel location of the chroma reference picture,
• wherein the 7-tap filter comprises seven filter coefficients, and
• the 4-tap filter comprises four filter coefficients.