A method and apparatus for video coding. The method operates by receiving pixel data associated with a current block at an encoder side or coded data associated with the current block to be decoded at a decoder side. The method further determines a candidate set comprising a plurality of candidate values and selects a first blending size for the first region and a second blending size for the second region from the candidate set. Then, the method determines a blending region around the partition line based on the first blending size and the second blending size and determines a first predictor for the first region and a second predictor for the second region. Finally, the method generates a blended predictor for the blending region by blending the first predictor and the second predictor, and encodes or decodes the current block by using prediction data comprising the blended predictor.