A method includes applying a common voltage to a display panel, digitally converting a feedback common voltage from the display panel, detecting an effective ripple signal exceeding a reference value based on the digitally converted feedback common voltage, comparing a total number of effective ripple signals detected during a first frame period with a threshold value, determining whether the effective ripple signals of the first frame period are crosstalk inducing signals based on a comparison result, and determining whether to change a polarity pattern of image data signals to be applied to the display panel during a second frame period based on a determination result in terms of the crosstalk inducing signal.