1. A method of estimating a motion in an image pickup device, the method comprising: dividing by the image pickup device, a photographed image into a plurality of image blocks; determining a weight value for a motion vector of each image block of the plurality of image blocks based on focus information and zoom magnification information; predicting the motion vector for each image block of the plurality of image blocks; and determining a global motion vector by applying, for each of the plurality of image blocks, the weight value determined for the motion vector for each image block of the plurality of image blocks to the corresponding predicted motion vector, wherein the determining the weight value comprises determining a weight function having a slope for the motion vector based on the focus information, and changing the slope of the weight function based on the zoom magnification information.