1. A method for identifying a generated position of a dynamic false contour generated when one field period is divided into a plurality of subfields having a relative luminance ratio different from one another, and gradation is shown on a display by combining the luminance of said individual subfields, the method comprising the step of detecting a pixel including a carry or a borrow in at least one subfield in an arrangement of gradation levels in said one field period of a plurality of pixels including the detected pixel arranged successively on said display when the gradation levels in said one field period change smoothly along said plurality of pixels.