1. The interactive desktop system comprising: a) an image capture system for capturing a captured image in a field of view of the image capture system, the captured image including an image of a portion of a source document, the image capture system having electronically controllable pan and zoom functions for adjusting the field of view; b) a display system for displaying a feedback image on the source document, the feedback image indicating to a user the captured image, the feedback image being visible to the image capture system; and c) a processor system coupled to the image capture system and the display system, the processor system responding to a user adjustment of the feedback image by adjusting at least a one of the pan function and the zoom function, wherein the processor system comprises: c1) a processor for executing instructions; c2) a memory coupled to the processor for storing the instructions in machine readable form, the instructions comprising the steps of: A) capturing a first image in the field of view of the image capture system while the feedback image is being displayed on the source document; B) capturing a second image in the field of view of the image capture system while the feedback image is not being displayed on the source document; C) generating a difference image from the first image and the second image; D) searching for the feedback image in the difference image; and E) when the feedback image is found in the difference image adjusting at least a one of the pan and zoom controls of the image capture to center the feedback image within the difference image.