1. An image display apparatus which displays a multi-gray-scale image, where the multi-gray-scale image is displayed in a time unit called TV field which is divided into N subfields which are respectively assigned luminance weights, and the multi-gray-scale image is expressed by illuminating desired subfields, the image display apparatus comprising: a selecting means for selecting a gray scale level among a plurality of gray scale levels in accordance with a motion amount of an input image signal, wherein the luminance weights are represented as W 1, W 2,... and WN, each of the plurality of gray scale levels is expressed by an arbitrary combination of 0, W 1, W 2,... and WN, and the motion amount is a change of the input image signal over time; and a subfield illuminating means for illuminating subfields corresponding to the selected gray scale level.