Title: Digital water mark embedding and extracting method and device
Application Number: 200610114048 Application Date: 2006.10.25
Publication Number: 1945622 Publication Date: 2007.04.11
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: G06T1/00
Applicant(s) Name: Beida Fangzheng Electronic Co., Ltd., Beijing Address:
Inventor(s) Name: Qi Wenfa;Li Xiaolong;Zhang Hua
Attorney & Agent: lixin
Abstract:
    The invention disclosed a digital watermark embedding and extraction method and device in the text images of black-and-white value. The embedding method includes locating the regions of effective characters in the text image, grouping the regions to count the number of black spots in each region, calculating the first pixel number need to turn off in each region according to the relative relationship of the number of black spots in each region, watermark strings, and the first step length, and overturning the pixels in each region according to the first number. The extraction method includes locating the regions of effective characters in the text image, grouping the regions to count the number of black spots in each region, extracting the bit strings of embedded watermark information according to the relative relationship of the number of black spots in each region. The invention can better resist the attack of printing, scanning and copying with good visual effects and a lot of embedded information, which has universal property in the field of digital printing.
Time: 10