1. A method for integration of a source object into a base image with an area overlapping the source object, the method comprising the steps of: identifying similar border pixels, that is, pixels on two sides of a border between the source object and the base image having differences from each other smaller than a first threshold; calculating characteristic values of the similar border pixels in the source object and the base image using an energy function; creating a tonal map using the characteristic values; dividing the source object and the overlapped area in the base image into regions by segmentation filtering; identifying similar regions in the source object, each of which, in the characteristic values, has a difference smaller than a second threshold from the similar border pixels in the source object and has a difference smaller than a third threshold from one of the regions in the overlapped area having a difference smaller than a fourth threshold from the similar border pixels in the overlapped area; and applying the tonal map to the similar regions in the source object.