1. An object image detection device for detecting one or more object images from an input image, comprising: an object image classification unit configured to determine whether the object images are included in an image having a predetermined orientation; an image orientation detection unit configured to detect an orientation of the input image; an image rotation unit configured to rotate the object image classification unit according to the detected orientation of the input image; and a detection unit configured to detect the object images from the input image by using the rotated object image classification unit.