1. A method of rendering user-specified image products, comprising the steps of: executing a plurality of user-interactive tasks relating to an image product, at least some of the user-interactive tasks specifying a portion of an image product; computing a change probability of further changes to a portion of the image product specified by at least one of the plurality of user-interactive tasks; and if the change probability is below a predetermined threshold, rendering the portion of the image product corresponding to the at least one of the plurality of user-interactive tasks specifying a portion of the image product.