Method and device for interpolating images by using a smoothing interpolation filter

A method of motion compensation, the method comprising:

• 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;
• generating a luma sample of a 2/4-pixel location included in the luma reference block by applying an 8-tap filter to luma samples of a integer pixel location of the luma reference picture;
• determining, in a chroma reference picture, a chroma reference block for prediction of a current block, by using a chroma motion vector of the current block;
• and
• generating at least one chroma sample of at least one of ⅛, 2/8 and ⅜-pixel locations included in the chroma reference block by applying a 4-tap filter to chroma samples of a integer pixel location of the chroma reference picture,
• wherein the 8-tap filter includes a first filter coefficient, a second filter coefficient, a third filter coefficient, a fourth filter coefficient, a fifth filter coefficient, a sixth filter coefficient, a seventh filter coefficient, and an eighth filter coefficient,
• a value of the first filter coefficient is equal to a value of the eighth filter coefficient,
• a value of the second filter coefficient is equal to a value of the seventh filter coefficient,
• a value of the third filter coefficient is equal to a value of the sixth filter coefficient,
• a value of the fourth filter coefficeint is equal to a value of the fifth filter coefficient, and
• the 4-tap filter includes four filter coefficients for interpolation.