1. A computer program product residing on a computer readable medium for causing a reading machine to operate in different modes that optimize performance for specific uses of the reading machine, the computer program product comprises instructions for causing the reading machine to: receive data that specifies a mode to use for processing an image; access a knowledge base to provide data to configure the computer program product for the specified mode, with the data including specific target visual elements that are expected to be encountered in processing images for the specified mode; capture one or several images; and process the one or several images to identify one or more of the target elements in the image using information obtained from the knowledge base.