Abstract: A method and system for allowing owners of a physical work, such as a book, to purchase an electronic version of the work by validating their ownership of the work using a personal electronic device, such as a smartphone, and marking the work. The owner is instructed to mark the work and to capture camera images of the work. The images are analyzed to identify the work, determine whether the work has been previously marked, and to verify that the work has been marked by the owner. Analysis may be performed remotely by a server in communication with the personal electronic device. Various means for authenticating ownership of the work are also disclosed, including 3D analysis, page curvature analysis, concurrent still image and video capture, detection of use of a video display to spoof the work, and geofencing.