Image processing device and method for plasma display panel

An image processing device and method of a plasma display panel are provided to display a clear image by reducing false contour noise and halftone noise according to motion information of a frame by a motion adaptive gradation method. An image processing method of a plasma display panel includes a luminance center grayscale generating step for expressing all grayscales by using only the grayscale positioned in a luminance central axis of the displayed light among all the grayscales displayed by combining subfields with different grayscale weighted values(ST1); a real grayscale generating step for generating all the grayscales displayed by combining the subfields with different gray level weighted values(ST2); a frame comparing step for comparing the change rates of grayscale values of the present and previous frames(ST3); a motion counting step for deciding that a motion is generated if the change rate of the compared grayscale value is over a critical value and then counting the number of pixels where the motion is generated(ST4); a hysterisis step for determining the form of the grayscale of the frame to be output if the counted motion degree is over a set reference value(ST5); and a multiplexing step for mixing and displaying the grayscales generated by the luminance center grayscale generating step or the real grayscale generating step during one frame, with varying the number of the grayscales(ST6).