| 摘要 |
<p>A method of encoding information in a document using a plurality of marks (104), the information comprising first data and second data, the method comprising the steps of encoding the first data using a first plurality of arrays of modulated marks disposed in a corresponding first plurality of tiles (610) spaced apart from each other at a first repeat rate (660); and encoding the second data using a second plurality of arrays of modulated marks disposed in a corresponding second plurality of tiles (680) spaced apart from each other at a second repeat rate (670); wherein: the second repeat rate is different to the first repeat rate; and the second plurality of tiles are embedded within the first plurality of tiles.</p> |
