A motion detecting apparatus, comprising: an object image acquiring unit arranged to acquire plural object images based on images respectively obtained from at least two cameras, the acquired plural object images including the object without a background; a motion-detection-area setting unit arranged to set respective motion detection areas in the acquired object images; and a motion detecting unit arranged to detect a motion of the object based on a determined amount of an image change in the respective motion detection areas between the acquired object images; wherein the object image acquiring unit comprises: a first image acquiring unit; a second image acquiring unit; a facial area detecting unit arranged to detect a facial area from a first image obtained from the first image acquiring unit or a second image obtained from the second image acquiring unit; a distance image acquiring unit arranged to acquire a distance image from first and second images; a mask creating unit arranged to create an image mask by identifying an area in the distance image corresponding to the detected facial area, calculating a distance d to the object using the distance information of the distance image corresponding to the facial area and then removing a portion corresponding to the background other than the object; and an image filtering unit arranged to produce an object image by filtering the first image or second images based on the created image mask. an object image acquiring unit arranged to acquire plural object images based on images respectively obtained from at least two cameras, the acquired plural object images including the object without a background; a motion-detection-area setting unit arranged to set respective motion detection areas in the acquired object images; and a motion detecting unit arranged to detect a motion of the object based on a determined amount of an image change in the respective motion detection areas between the acquired object images; wherein the object image acquiring unit comprises: a first image acquiring unit; a second image acquiring unit; a facial area detecting unit arranged to detect a facial area from a first image obtained from the first image acquiring unit or a second image obtained from the second image acquiring unit; a distance image acquiring unit arranged to acquire a distance image from first and second images; a mask creating unit arranged to create an image mask by identifying an area in the distance image corresponding to the detected facial area, calculating a distance d to the object using the distance information of the distance image corresponding to the facial area and then removing a portion corresponding to the background other than the object; and an image filtering unit arranged to produce an object image by filtering the first image or second images based on the created image mask. a first image acquiring unit; a second image acquiring unit; a facial area detecting unit arranged to detect a facial area from a first image obtained from the first image acquiring unit or a second image obtained from the second image acquiring unit; a distance image acquiring unit arranged to acquire a distance image from first and second images; a mask creating unit arranged to create an image mask by identifying an area in the distance image corresponding to the detected facial area, calculating a distance d to the object using the distance information of the distance image corresponding to the facial area and then removing a portion corresponding to the background other than the object; and an image filtering unit arranged to produce an object image by filtering the first image or second images based on the created image mask.