Disclosed herein is an image processor including: a random number sequence generation section adapted to generate a random number sequence; a random number-superimposed luminance variable generation section adapted to generate a random number-superimposed luminance variable by superimposing the random number sequence on a luminance variable; and a random number-superimposed image signal generation section adapted to generate a random number-superimposed image signal by superimposing the random number-superimposed luminance variable on an image signal.