1. A method of image augmentation for an image of a book, the book having at least one substantially rigid leaf, the method comprising the steps of: capturing an image of the book; detecting at least a portion of at least one fiduciary marker of the book within the image; estimating a placement of a spine of the book in the image based upon the detected at least the portion of the at least one fiduciary marker; hypothesising a plurality of possible positions for edges of a rigid leaf being turned in the book based upon the estimated placement of the spine of the book; processing the image of the book to identify edges within the image; comparing elements of the identified edges of the processed image with the hypothesised plurality of possible positions for edges of the rigid leaf; selecting one of the hypothesised plurality of possible positions for edges of the rigid leaf that best coincides with the compared elements of the processed image as representative of the position of the rigid leaf being turned in the book; and augmenting the image of the book with a virtual graphic element arranged in accordance with the selected representative position of the rigid leaf.