| 摘要 |
<p>According to the present invention; a matrix code as a data carrier for readable data, i.e. the encoded information to be stored, and a graphical structure for the chosen watermark subject are combined using conventional computers for image processing. The combination of the matrix code and the graphical structure which is the new image is reproduced as a watermark in the substrate of the security document using conventional methods for producing watermarks. A main advantage of having a matrix code embedded in a watermark background image is that the matrix code is not visible for the general public, but the data is readable by reading the watermark, extracting the matrix code from the background image and decoding the data from the matrix code. It is an important aspect of the invention that the encoded data allow the identification and/or authentication of the security document as well as the assessment of the quality of watermark by comparing the decoded data with predetermined data.</p> |
