Frame rate up conversion (FRUC) is a conversion process between any two display formats with different frame rates. It can be used in HDTV application and in low bandwidth video coding. In this paper

a scene change detection method is proposed to detect whether the scene has changed. If the scene change occurs

the extrapolation technique will be used

otherwise

the interpolation will be chosen. Second，a motion vector processing method is adopted to correct and refine the unreliable motion vectors with variable block sizes

so the visual artifacts due to incorrect motion vectors can be eliminated and the object boundaries and structure information can be preserved. Experimental results show that the proposed algorithm provides good subjective and objective quality.