On-screen display (OSD) image processing method

An on-screen display (OSD) image processing method for generating an interpolated frame from a previous frame and a current frame, the interpolated frame comprising a plurality of interpolated blocks having OSD blocks, non-OSD blocks and extended OSD blocks, and the OSD image processing method comprising:

• performing motion compensation to generate motion compensation (MC) data according to a first motion vector referring to the previous frame and a second motion vector referring to the current frame;
• generating zero-motion data according to a zero-motion vector referring to the previous frame and the current frame, wherein a value of the zero-motion vector is zero;
• and
• blending the MC data of a first weight and the zero-motion data of a second weight to generate each of the plurality of interpolated block as a processed block;
• wherein when number of pixels having OSD data in the processed block is less than a first positive threshold and larger than a second positive threshold, the processed block is determined as the extended OSD block, and the second weight of the extended OSD block is less than the second weight of the OSD block.