Method and apparatus for affine inter prediction of chroma subblocks

The present invention relates to a motion vector derivation method and apparatus for chroma sub-block affine inter prediction according to a chroma format. The method comprises the steps that chroma scaling factors in the horizontal direction and the vertical direction are determined according to chroma format information, and the chroma format information represents the chroma format of a current image to which a current image block belongs; determining a set of luma sub-blocks (S) of a luma block from the value of the chroma scaling factor; a motion vector of a chroma sub-block of a chroma block is determined from motion vectors of one or more luma sub-blocks in the set of luma sub-blocks (S). 本发明涉及一种根据色度格式进行的用于色度子块仿射帧间预测的运动矢量推导方法及装置。所述方法包括：根据色度格式信息，确定水平方向和垂直方向上的色度缩放因子，其中，所述色度格式信息表示当前图像块所属的当前图像的色度格式；根据所述色度缩放因子的值，确定亮度块的亮度子块集合(S)；根据所述亮度子块集合(S)中的一个或多个亮度子块的运动矢量，确定色度块的色度子块的运动矢量。