4 results about "Watermark algorithm" patented technology

This invention discloses a method and apparatus for evaluating the robustness of image watermarking. The method includes: acquiring an original image dataset; printing watermarks on a portion of the original images in the original image dataset using the watermarking algorithm to be evaluated, forming a watermarked image dataset; attacking all images in the watermarked image dataset to obtain an attacked image dataset; performing watermark recognition on all images in the attacked image dataset to obtain watermark recognition results; the watermark recognition results include the true positive rate and the false positive rate; using a preset image quality measurement algorithm, calculating the image quality measurement values ​​before and after the attack for each watermarked image, as the image quality degradation result; determining the image watermark robustness evaluation result based on the watermark recognition result and the image quality degradation result; the image watermark robustness evaluation result includes an image watermark robustness evaluation report. This invention provides a complete, systematic, and mature method for evaluating watermarking algorithms.

This invention provides a data synchronization method and apparatus. Through a visual interface, the data source and target cluster index parameters are configured. A data synchronization task is created based on the data source and index parameters. The task's time period and triggering rules are set. The task is scheduled according to these rules. An incremental watermark algorithm is used to read data from the data source. Write nodes are dynamically allocated based on load. A search interface combining HTTP / Socket dual protocols and local caching is provided to query data for business scenarios. This improves development efficiency, ensures data consistency and reliability, enhances resource utilization, and reduces data synchronization time. It significantly improves the data synchronization efficiency and system stability of distributed systems and is suitable for high-concurrency, multi-source, heterogeneous data synchronization scenarios.

The application provides a multi-bit audio watermarking method based on phase distribution and high-efficiency bit mapping, and belongs to the field of audio information hiding. The application divides multiple independent phase subintervals based on the natural distribution characteristics of phases, and can realize one-to-many mapping from single feature to multi-bit watermarking by constructing unique phase features in the phase subintervals corresponding to watermarking information. In addition, the application introduces an optimization strategy, and can realize automatic phase redistribution. The application can significantly reduce the number of subspaces / feature modes required for multi-bit embedding, and reduce the design difficulty of the multi-bit watermarking algorithm. In addition, since an automatic phase redistribution algorithm based on optimization constraints is adopted, the algorithm can more effectively balance the inaudibility and robustness.