Image digital copyright protecting method and image digital copyright protecting system based on frequency domain digital watermarking algorithm

Abstract

The invention provides an image digital copyright protecting method based on a frequency domain digital watermarking algorithm. The method comprises the steps of performing coding of character information which comprises copyright information for obtaining an image sequence that is obtained through combining definite-number binary-value image templates, and embedding the binary-value image sequence into an image according to image characteristic points and a wavelet transform technique; calculating the size of the image sequence for keeping robustness of the algorithm, and generating an alarm when the size of the image sequence is overlarge; and for resisting rotation and scaling attacks, embedding pre-arranged template linear points in an annular Fourier transform area of SIFT characteristic points of the image. In extraction, a rotation and scaling deformation parameter which is bear by the image is estimated through analyzing distribution of the template linear points; the parameter is used for restoring the image and then extraction is performed; a extracted watermarking binary-value image is restored to a watermarking character sequence through matching with a preset template image according to an encoding algorithm; and whether the watermarking sequence is totally extracted is checked by means of a CRC32 algorithm. The image digital copyright protecting method has high robustness and settles a problem of incapability of simultaneously resisting multiple kinds of attacks in an existing image algorithm, particularly cutting and rotation scaling geometric attacks.

Description

technical field [0001] The invention relates to the technical field of geographic information copyright protection, in particular to an image digital copyright protection method and system based on a frequency domain digital watermark algorithm. Background technique [0002] Image data, as a geographic base map, is an important basic resource. The collection, storage, editing, and processing of image data requires a lot of manpower, material and financial resources, so data theft, illegal copying, and other infringements are prone to occur. Not long after Google launched the online electronic map service, many tool software for downloading Google electronic map image data appeared on the Internet, and the image data can be obtained easily. Regularly and visibly embedded in the published electronic map image data to swear copyright. It can be seen that the image data must be processed by certain copyright protection technical means before it can be publicly released. The ab...

AI Technical Summary

Problems solved by technology

[0005] At present, the image algorithm cannot resist multiple attacks at the same time, especially the problems of cropping, rotation and scaling geometric attacks

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