1. A color balancing apparatus for multiple image synthesis, the color balancing apparatus comprising: a computer processor; a non-transitory data storage device; computer readable code stored in the non-transitory data storage device and executable by the computer processor, the computer readable code defining functional units which include: an automatic white balance unit, with respect to each of a plurality of input images that are obtained by sequentially capturing adjacent scenes, to compare a neutral color representing the input image with chromaticity of standard sources that are predefined, determine a neutral color standard source among the standard sources as a standard illuminant, and perform a white balance on the input image based on the standard illuminant; a wide-area image synthesis unit to generate a single wide-area image by synthesizing the plurality of input images subjected to the white balance based on the standard illuminant; and a color correction unit, with respect to two adjacent input images in the wide-area image, to perform a color correction based on the input image whose neutral color better approximates the standard illuminant than the neutral color of another input image approximates the standard illuminant.