1. A display apparatus for receiving image data and displaying an image according to pixel data generated utilizing the image data, the image comprising a plurality of pixels, the display apparatus comprising: an error diffuser for generating the pixel data by diffusing to a current pixel among the plurality of pixels an error corresponding to a portion of the image data for at least one first pixel among the plurality of pixels according to at least one first diffusion factor and an error corresponding to a portion of the image data for a second pixel among the plurality of pixels according to a second diffusion factor, wherein the error diffuser sets the second diffusion factor differently based on whether or not the current pixel is within a certain number of uppermost lines of the image; a plasma display panel (PDP) for displaying the image; a display controller for controlling the PDP to display the image; and a subfield information generator for assigning brightness weight to the pixel data to generate subfield information utilized by the display controller to control displaying of the image.