1. A frame prediction system, comprising: an initializing module initializing a first image block, and the first image block having a plurality of pixels; a providing module providing a first centroid and a first motion vector of a second image block; a location lookup module coupled to the initializing module and the providing module for finding a location according to the first centroid, and generating a first weight and a second weight according to a relation of each of the pixels with the first centroid and the location, such that the plurality of pixels has a first minimum pixel intensity error in the first image block; a vector lookup module coupled to the providing module and the location lookup module for finding a second motion vector which gives a second minimum pixel intensity error to the plurality of pixels in the first image block according to the first centroid, the first motion vector, the location, the first weight and the second weight; and a processing module coupled to the providing module, the location lookup module and the vector lookup module for sequentially calculating a predictive intensity value of each of the pixels according to the first motion vector, the second motion vector, the first weight and the second weight.