A method that highlights a depth-of-field (DOF) region of an image and performs additional image processing by using the DOF region. The method includes: obtaining a first pattern image and a second pattern image that are captured by emitting light according to different patterns from an illumination device; detecting a DOF region by using the first pattern image and the second pattern image; determining weights to highlight the DOF region; and generating the highlighted DOF image by applying the weights to a combined image of the first pattern image and the second pattern image.