1. An apparatus for generating feature data of an image, comprising: a feature point determination unit for determining feature points from an image and extracting feature point information for the determined feature points; a feature point filtering unit for determining one or more of the feature points determined by the feature point determination unit to be final feature points; and a feature data generation unit for generating feature data of the image based on the final feature points determined by the feature point filtering unit and feature point information for the final feature points, wherein the feature point information extracted by the feature point determination unit includes intensities of the feature points, wherein the feature point filtering unit determines a point having a larger intensity than other points located in a surrounding area of a corresponding feature point to be a final feature point, based on the intensities of the feature points, and wherein the feature point filtering unit determines important points R 2 (c i ) satisfying the expression R 2 ( c i ) = { c i  f ( c i ) > max R 1 ( c i ) [ f ( c i ) ] × T 1 } among the points located in the surrounding area of the feature point, where c i denotes an i-th feature point, f(c i ) denotes intensity of the i-th feature point, R 1 (c i ) denotes a set of points in the surrounding area of the feature point, max R 1 ( c i ) [ f ( c i ) ] denotes a maximum value of intensities of R 1 (c i ) and T 1 denotes a threshold, and determines a feature point satisfying the expression f ( c i ) > ∑ c i ∈ R 2 ( c i ) f ( c i ) # ( R 2 ( c i ) ) × T 2 to be the final feature point, where # denotes an operator for obtaining a size of the set and T 2 denotes a threshold.