1. A driving method for driving a liquid crystal display having a plurality of pixel array areas, each pixel array area including plural pixels, the driving method comprising: generating a plurality of grey-level signals corresponding to the pixels based on input image data; converting the grey-level signals corresponding to the pixels into a plurality of weightings; generating a weighting sum by summing up the weightings corresponding to the pixel array area; and performing a pixel data writing operation of the pixel array area based on a polarity inversion mode corresponding to a weighting range into which the weighting sum falls.