Abstract: A hybrid system for identifying a printed page. The system includes: (i) the printed page having human-readable content and a coding pattern printed in every interstitial space between portions of human-readable content, the coding pattern being either absent from the human-readable content or unreadable when superimposed with the human-readable content; and (ii) a handheld device for overlaying and contacting the printed page. The handheld device includes: a camera for capturing page fragment images; and a processor configured for: decoding the coding pattern and determining the page identity in the event that the coding pattern is visible in and decodable from the captured page fragment image; and otherwise initiating OCR or SIFT techniques to identify the page.

Abstract: A handheld display device for displaying an image of a physical page relative to which the device is positioned. The device includes: an image sensor for capturing an image of the physical page; a transceiver for receiving a page description corresponding to a page identity of the physical page; and a processor configured for: rendering a page image based on the received page description; estimating a first pose of the device relative to the physical page; estimating a second pose of the device relative to a user's viewpoint; and determining a projected page image using the rendered page image, the first pose and the second pose; and a display screen for displaying the projected page image. The display screen provides a virtual transparent viewport onto the physical page irrespective of a position and orientation of said device relative to said physical page.

Abstract: A method of displaying an image of a physical page relative to which a handheld display device is positioned. The method includes the steps of: capturing an image of the physical page using an image sensor of the device; determining a page identity for the physical page; retrieving a page description corresponding to the page identity; rendering a page image based on the retrieved page description; estimating a first pose of the device relative to the physical page; estimating a second pose of the device relative to a user's viewpoint; determining a projected page image for display by the device; and displaying said projected page image on a display screen of said device. The display screen provides a virtual transparent viewport onto the physical page irrespective of a position and orientation of the device relative to the physical page.