A controller acquires video data, determines provisional luminance values for backlight blocks based on the video data, determines an adjustment coefficient for a backlight block of interest selected from the backlight blocks, determines an adjusted luminance value for the backlight block of interest based on the provisional luminance value and the adjustment coefficient for the backlight block of interest, and controls the backlight block of interest in accordance with the adjusted luminance value. In determining the adjustment coefficient, the controller calculates a statistic of provisional luminance values for reference backlight blocks including backlight blocks adjacent to the backlight block of interest, calculates a relative value of the statistic with respect to the provisional luminance value for the backlight block of interest, and determines the adjustment coefficient for the backlight block of interest based on the relative value and a predefined function.