Database digital watermark extraction method

The invention discloses a database digital watermark extraction method. The method is characterized by comprising the steps of traversing a target database watermarks of which need to be extracted, extracting position information and data information of watermark sites, conducting detection and decoding on the position information to obtain a final sample sequence H', and conducting detection anddecoding on the data information to recover original information of the watermark sites. Compared with other methods, the method has the advantages that the watermark data accuracy rate is higher, higher authentication accuracy is thus obtained, and therefore a copyright protection effect is improved; when the database is not attacked, the original data can be completely recovered, and when the database is attacked, the data accuracy rate of the recovered original data is relatively higher than that of other methods; by compressing matrix storage positions for extraction, the calculation costcan be greatly reduced. 本发