Digital watermark processing method and device for print document traceability

Abstract

The embodiment of the invention provides a digital watermark processing method and device for print document traceability. The method comprises the steps that a text document is converted into an image, and an image is divided into text images corresponding to each text in the text document; the Euler number of texts in each text image is calculated, and the digital feature corresponding to the text image is determined according to the Euler number parity; the digital watermark information to be embedded in each text image is acquired, and whether the digital feature matches the digital watermark information to be embedded is determined; if the digital feature does not match the digital watermark information to be embedded, the topological structure of the texts in the text image is changed; and the Euler number of the texts with changed topological structure is calculated, so that the digital feature of the Euler number matches the digital watermark information to be embedded. According to the embodiment of the invention, the output security of paper confidential documents can be improved.

Description

technical field [0001] The invention relates to the field of information security, in particular to a digital watermark processing method and device for traceability of printed documents. Background technique [0002] With the rapid development of electronic information technology and the continuous improvement of the informatization level of all sectors of society, various multimedia files such as electronic documents, images, videos, etc. are widely used in people's daily life. Among them, electronic documents have the advantages of fast creation, space saving, and convenient transportation, and have become a convenient carrier for information exchange. The daily documents and even confidential information of many enterprises and units are stored and transmitted in the form of electronic documents. These documents contain a variety of information and have great economic value and application value. However, for the printed paper documents and their copies, due to the lac...

AI Technical Summary

Problems solved by technology

[0005] However, through the existing digital watermark processing method for traceability of printed documents, the watermark capacity is too small for the line spacing algorithm; When copying and scanning, the pixels at the edge of the text may be flipped, resulting in a change in the word spacing. In addition, if the document is scaled during the copying and scanning process, the word spacing difference will not reach the threshold. If you want to resist these attacks, you need Sacrificing the transparency of the watermark and adjusting the spacing to a greater extent makes it difficult to balance the transparency and robustness of the watermark information, resulting in poor usability of the watermark information and reducing the security of paper confidential document output

Images