Abstract:

Because of too many non-watermark data points, current robust watermarking algorithms can hardly detect the watermark in vector geographic data when attacked by joining and updating. Aiming at this issue, we present a digital watermarking algorithm based on point positioning by using fragile watermarking technology. Along with the robust watermark embedding, the fragile watermark which formed by features of vector geographic data coordinates is embedded in the data using the idea of quantization according to accuracy requirements. And the tamper can be enclosed with coordinate for each data point through the fragile watermarking detecting. So we can exclude the interference of non-watermark data points and make the robust watermarking algorithm detect copyright information reliably for vector geographic data. The experiments show that the proposed algorithm can improve the validity of the watermark detection results, for it can resist the attacks of data joining and updating effectively, and exclude the interference of non-watermark data points.

Key words: vector geographic data, fragile watermarking, point positioning, data joining, data updating