1. A sub-pixel rendering method, performed by a driving chip of a display, comprising: receiving, by the driving chip of said display, a digital image; dividing, according to color values of image pixels in the digital image, the image pixels into boundary region pixels and continuous region pixels; and generating a plurality of screen pixels on a screen, each screen pixel at least including one red sub-pixel, one blue sub-pixel, and one green sub-pixel, one of the plurality of screen pixels being used to correspondingly display one of the image pixels, wherein adjacent screen pixels for displaying the continuous region pixels share sub-pixels, and each screen pixel for displaying the boundary region pixels exclusively uses its own subpixels.