Provided is an image registration device including a first feature vector magnitude calculating unit calculating magnitudes of feature vectors corresponding to any one first feature point among feature points of a reference image to create a first magnitude value, a second feature vector magnitude calculating unit calculating magnitudes of feature vectors corresponding to any one second feature point among feature points of a target image to create a second magnitude value, a magnitude difference calculating unit receiving the first and second magnitude values and calculating a difference between the received first and second magnitude values to create a third magnitude value, a first threshold value creating unit creating a first threshold value on the basis of the first magnitude value and a magnitude ratio, and a magnitude difference determining unit receiving the third magnitude value and the first threshold value, and determining a magnitude difference.