1. An apparatus for improving quality of an enlarged image, comprising: a first image input unit and a second image input unit configured to output a first image and a second image, respectively, which are obtained by capturing a same subject from different positions, spaced apart by a predetermined gap; a first image processor configured to convert a resolution of the first image to a preview resolution; a display configured to display the first image from the first image processor; a second image processor configured to crop an area corresponding to the selected area from the second image, when an area to be enlarged in the displayed first image is selected; and a controller configured to control the display to display the cropped area on the first image in an overlaying manner.