1. A method of generating an interpolation image between a first reference image of an input video and a second reference image thereof, comprising: dividing each of the first reference image and the second reference image into a plurality of reference regions each including a plurality of pixels, executing a correlation operation between the first reference image and each of at least two first destination images located before and after the first reference image in terms of time and a correlation operation between the second reference image and at least one second destination image corresponding to the second reference image to derive a plurality of motion vectors between the first reference image and each of the first destination images, and a plurality of motion vectors between the second reference image and the second destination image, for each reference region of the reference regions; obtaining a correlation value between the reference region and a corresponding region of at least one of the first destination images and the second destination image that is indicated by each of the motion vectors to determine the reference region as a high correlation region or a low correlation region; generating a plurality of interpolation image candidates between the first reference image and the second reference image using the reference region determined as the high correlation region; and mixing the plurality of interpolation image candidates to produce an interpolation image.