1. An image processing system comprising: one or more processors coupled to one or more memories; an input arranged to receive a plurality of digital images for automatically forming a digital collage; a first module implemented by the one or more processors, providing an application programming interface arranged to be used by an application in order to control the image processing system, said first module being configured to modify dimensions of the received images so that each of the images matches a normalized dimension requirement; a plurality of prior compute modules, implemented by the one or more processors each having an interface to the first module, and each arranged to compute information to be used in determining rank and identifying regions of interest in the plurality of images; and an image synthesis module, having an interface to the first module, implemented by the one or more processors, and arranged to automatically form the digital collage from at least some of the plurality of digital images on the basis of the information computed by the prior compute modules.