1. A method for building a map for mobile robot localization, comprising: detecting and temporarily registering a landmark from a first image acquired at a first location by the mobile robot; extracting the corresponding landmark from a second image acquired at a second location by the mobile robot; estimating the temporarily registered landmark from the second image based on moving information and the temporarily registered landmark information; and mainly registering the temporarily registered landmark if it is determined that a matching error is in a range of a predetermined reference error by calculating the matching error between the temporarily registered landmark and the estimated landmark; wherein the temporarily registering of the landmark includes: dividing the first image into a plurality of sub-images and detecting features by calculating a magnitude of a brightness change and a phase of a brightness change in the plurality of sub-images; and searching features at which the brightness change and the magnitude of the phase of the brightness change are maximal among the plurality of features detected from each sub-image and setting the features as the temporarily registered landmark; and wherein the magnitude in the brightness change is obtained by taking a square root of a sum of a horizontal brightness change and a vertical brightness change of each sub-image.