Backgrounds as information carriers for printed documents

This paper presents a method of embedding and recovery of a large amount of data on printed documents. The proposed method is characterized by the following points: (1) As the medium for recording the data, backgrounds (white space) of pages are utilized. Since white space is dominant in ordinary pages, this enables us to record a large amount of data. (2) As the representation of data, an arbitrary figure (such as a logo mark of a company) is stippled to obtain a set of points, each of which is superimposed on a page image. This allows us to prevent the appearance of a page from deteriorating, since stippled figures play a role of background patterns on printed documents. The experimental results show that the method is capable of both recording 7.8KB of data and reading the embedded data with the accuracy of 99%.