1. A method of evaluating the importance of images in a collection by executing a software program stored in a non-transitory, tangible, computer-readable storage medium with a computer processor, the method comprising the steps of: the processor analyzing two or more attributes of a plurality of images from the collection that appear in a photo-collage, wherein the attributes comprise at least two selected from the group consisting of image layout, image position, image size, image orientation, and image shape; the processor automatically assigning an importance ranking to each of the plurality of images from the collection that appear in the photo-collage, wherein each importance ranking is responsive to weighted importance metrics associated with the two or more attributes; and the processor storing the assigned importance rankings in association with the collection of images.