Watermarking Application System for Map Content Distribution

摘要

Many people use digital maps in their car navigation systems or on the Web. On the other hand, the distribution service providers are still concerned about illegal copying, which may damage their businesses. Digital watermark technology that can embedidentifier into digital content is expected to help with this problem. While copyright protection using digital watermark for multimedia content has received much attention, however, watermark applications for digital maps have not been discussed sufficiently. The effective usage of digital watermarks is analyzed in the context of an assumed map content distribution model. The technical requirements are also clarified for copyright claims, user tracking and resource management. Application systems using digital watermark technology are proposed for both vector maps and raster maps. As a watermark for a vector map, new information can be appended to already embedded information. The watermark then survives through the daily operation of a GIS system. Our implementation and evaluation shows that the proposed system satisfies the requirements.