1. A method of recognizing a user's dynamic organ for use in an electric-using apparatus, the method comprising: comparing a background image and a target image, which are inputted through an imaging element, to detect a candidate region including portions of the target image that are different between the background image and the target image; scanning the candidate region using a window; generating a histograms of oriented gradients (HOG) descriptor of a region of the target image that is scanned when it is judged that the scanned region includes a dynamic organ; measuring a resemblance value between the HOG descriptor of the scanned region and a HOG descriptor of a query template for a gesture of the dynamic organ; and determining that the scanned region includes the gesture of the dynamic organ when the resemblance value meets a predetermined condition, wherein detecting the candidate region includes: dividing each of the background image and the target image into regions; measuring another resemblance value between the corresponding divided regions of the background image and the target image; and adding the divided region of the target image to the candidate region when the another resemblance value meets another predetermined condition, and wherein the another resemblance value is a resemblance value between HOG descriptors of the corresponding divided regions of the background image and the target image, and wherein the HOG descriptors of the corresponding divided regions of the background image and the target image are generated based upon HOS (high order statistics) maps that are generated using HOS information for brightness of the background image and the target image, respectively.