To use the following pages, press and hold the left mouse button, then move the mouse to slide the red layer into alignment with the blue layer. Ideally, the red and blue layers would line up, except for places where the two images are absolutely different.
These images show comparisons between the same page from two different instances of a book. The blue layer is an image from our control copy of the book. The red layer is an image from another instance of the book. The red layer has been morphed to (hopefully) bring it into alignment with the control copy. test comparison 1,> test comparison 2, test comparison 3, and a smaller version of test comparison 1