1. An image quality analysis method for a display device, comprising the steps of: outputting an image pattern to the display device for a first period of time; dividing a screen display region on which the image pattern is displayed into a plurality of sub-regions; producing first measurement data corresponding to image quality during the first period of time for the plurality of sub-regions; outputting the image pattern to the display device for a second period of time; producing second measurement data corresponding to image quality during the second period of time for the plurality of sub-regions; normalizing the image pattern displayed on the screen display region; and quantitatively detecting an output level of image sticking of the image pattern from the normalized image pattern using the first measurement data and the second measurement data.