Text watermark embedding and extracting method based on character structure characteristics

Abstract

The invention relates to a text watermark embedding and extracting method based on character structure characteristics, which comprises the following steps: 1) according to the used word frequency, building a character object set, modifying characteristic points of the character objects to obtain a new work stock file; 2) installing the new work stock file at a computer terminal and printing the text, when printing and outputting the text, intercepting and capturing the text content data and analyzing the character objects, dynamically substituting watermark information to the character objects in the character object set; and 3) obtaining digital image data of the printed text by an image copying device, analyzing characteristic point information of each character designated location in the text image, and extracting the watermark information. The quantity of the carrier objects of the embedded watermark can be a lot; and the extracting precision of the watermark information is relatively high. At the same time, the modification and analysis principles of the character structure characteristic information are simple and clear; the character structure characteristic information is normalized, so that zoom and attack at unequal resolution ratio can be resisted; and the robustness is relatively high.

Description

technical field [0001] The invention belongs to the technical field of document protection, and relates to a method for embedding and extracting a digital watermark, in particular to a method for embedding and extracting a digital watermark based on character structure features in a text file. Background technique [0002] As the main way of disseminating information, text exists widely in electronic and paper media. Paper documents can be distributed in the form of printing, scanning, and copying; electronic documents can be copied and copied conveniently. Since the contents of documents are easily obtained and tampered with illegally during the dissemination of document information, the protection of important documents is particularly important. [0003] Text watermarking technology plays an active role in document-based information security. Some identifying information, such as document generation time, document ownership, etc., is hidden in confidential document data...

AI Technical Summary

Problems solved by technology

[0011] The present invention provides a text watermark embedding and extraction method based on character structure features, which is used to solve the problem of small amount of watermark information in the prior art, low watermark extraction and recognition accuracy, and inability to reduce image zooming deformation and inequality in the process of image acquisition. Errors and other shortcomings caused by resolution duplication, and further solve the problem of correctly extracting watermark information from image files taken by low-resolution image duplication devices such as digital cameras and mobile phones

Images