Research And Implementation Of Anti-printing Scanning Digital Watermarking Algorithm

The development of information technology has brought great convenience to people's production and life.With the improvement of information exchange convenience,digital copyright awareness has also been developed.Printed matter is an important medium for information exchange,and its demand for information security is increasing day by day,especially for printer chips,which is highly robust and easy to handle.The watermark algorithm has practical significance for the printer chip.However,the robustness of the existing digital watermarking algorithm cannot meet the printing and scanning application scenarios,especially the watermark information cannot be correctly extracted under the distortion caused by the printing scan.This paper mainly studies how to embed digital watermark information in printed works,and can extract the original watermark information after scanning to achieve the purpose of information hiding.In this paper,by analyzing the influence of print scanning on image and digital watermarking algorithms,the digital watermarking algorithm against print scanning and its hardware architecture are designed.In this paper,the variation relationship of two-dimensional discrete wavelet transform coefficients before and after printing scanning is analyzed.It is determined that the sign of the two-dimensional discrete wavelet transform tends to be unchanged before and after the printing scan.A digital watermarking algorithm based on two-dimensional discrete wavelet transform is proposed.The original image is subjected to block processing,and each sub-image is embedded with a watermark,and different weights of each sub-image are allocated in combination with the image texture in the extraction process,and the extracted watermark is weighted and averaged,thereby improving the reliability of the extraction.Experiments show that in the print scan scenario,the robust watermark can realize watermark extraction and better identify the original watermark information.This paper analyzes the basic principle of text watermarking,and combines the text watermarking algorithm of document structure to design a text digital watermarking algorithm based on punctuation eigenvalues.Aiming at the characteristics of Chinese character number,a processing flow for extracting the symbol feature value in text is designed,and the feature value is adjusted to embed a series of information with value 0 or 1.After the print scan,the information can be extracted by a fixed recognition algorithm.The algorithm has high robustness and increases the watermark capacity to a certain extent,and can resist printing scan attacks.Then,for the image watermarking algorithm proposed in this paper,a special processor for printer chip and application development of algorithm are designed.In combination with printer image processing application specificity,a dedicated processor instruction set and architectural design are designed.Combined with the dedicated processor,the data processing flow and data storage mode of the algorithm are designed and developed,and the algorithm is optimized to improve the performance of the algorithm.The optimized algorithm can achieve higher computational speed,which proves the practicality of the technology in practical application environments.Finally,combined with the problems solved in this paper and the results achieved,the problems in the research process are sorted out and the next step is clarified.