1. A method for combining a plurality of new images into a preexisting database, the method using a processor to perform the steps of: receiving the plurality of new images; designating the preexisting database, wherein the designated preexisting database stores chronologically ordered images, wherein the stored chronologically ordered images in the designated preexisting database were previously classified into database event groups based upon a time difference threshold, and wherein images in the database event groups were previously classified into database event subgroups based upon an image similarity measure; ordering the received plurality of new images into chronological order to form an ordered sequence of new images; forming new image clusters by analyzing the formed ordered sequence of new images using the image similarity measure to determine image cluster boundaries between consecutive images in the formed ordered sequence of new images; selecting a representative image in each of the formed new image clusters; designating a segment of the designated preexisting database, wherein the stored chronologically ordered images in the designated preexisting database chronologically overlaps the received plurality of new images; and assigning each of the formed new image clusters to a corresponding database event group and a corresponding database event subgroup within the designated segment of the designated preexisting database by optimizing a joint match score constrained by the chronological ordering of the received plurality of new images being maintained, wherein the joint match score is responsive to image similarity measures calculated between the selected representative image in each of the formed new image clusters and images in the database event subgroups.