An image detecting device includes a color image sensor configured to sense visible light and to output color image data based on the sensed visible light; a first infrared lighting source configured to provide first infrared rays to a subject; a second infrared lighting source configured to provide second infrared rays to the subject; a mono image sensor configured to sense a first infrared light or a second infrared light reflected from the subject and output infrared image data; and an image signal processor configured to, measure an illuminance value based on the color image data, measure a distance value of the subject based on a portion of the infrared image data corresponding to the first infrared light, and obtain an identification image of the subject based on the illuminance value, the distance value, and a portion of the infrared image data corresponding to the second infrared light.