Method and device for localized blind watermark generation and detection

Abstract

The invention discloses a method and device for localized blind watermark generation and detection. The generating method may include the steps of: generating an N-dimensional pseudo-random initial sequence according to a preset key, and appending the initial sequence to the initial sequence according to the bit position, thereby generating a 2N-dimensional sequence; extracting the first 2N coefficients of image feature points A coefficient sequence is formed, and the parity of the coefficient sequence is obtained according to the parity of corresponding bits of the 2N-dimensional sequence. The present invention can carry out redundant expansion of the watermark data, increase the inspection data with a larger scale than the original bit data, and then embed it into the transformation domain of the image feature point neighborhood; The sequence is checked on a bit-by-bit basis, and based on the check result, it is determined whether a watermark is embedded near the point, which can improve the efficiency of watermark detection.

Description

Technical field [0001] The present invention relates to watermark detection technology, in particular to a method and device for localized blind watermark generation and detection. Background technique [0002] Digital watermark is an invisible mark embedded in image, video or audio data, which can be used for copyright protection, authentication and tracking of multimedia data. [0003] In digital watermarking technology, according to the watermark extraction process, it can be divided into two types: plain text watermark and blind watermark. The plain text watermark needs the original data to be inserted, while the blind watermark only needs the key. Generally speaking, plaintext watermarking is robust, but the storage cost is too large to meet actual needs; blind watermarking is the research direction of watermarking algorithms. [0004] Image watermarking technology can be divided into global embedding and local embedding according to the way of watermark embedding. Global emb...

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Problems solved by technology

[0006] The above-mentioned localized blind watermarking technology has the following disadvantages: watermark detection still depends on the key, and in the process of detection, if there is no key, it is impossible to determine whether there is a watermark in the image;

[0007] When performing similarity matching on watermark information, the confidence of each bit in the default watermark information space is equal when matching, and in some cases it cannot be matched accurately, for example: suppose the unknown sequence is 11111, and the watermark A is 11110, Watermark B is 01111. At this time, it is impossible to determine which is more credible when two different watermarks, A and B, have the same matching value with the same extracted sequence; There is only one bit difference, so it is impossible to judge whether the unknown sequence is watermark A or watermark B

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