二维工程图数字水印

In the face of on-limits internet and technology of information disposal，the problems of copyright protect and information security become more and more salient. It is necessary to solve the problems at once. As one of the most potential technology，the watermarking has used widely. So it becomes a hotspot of copyright and tortuous survey. From the early airspace to commutation area and based on physical model，the disquisitive extension has developed widely.The main work contain encrypt the picture of watermark, and Aim at lots of lines，circles and arcs in engineering chart，the commutation arithmetic of length and scale is one of the most effective arithmetic. At last，it set out a validate arithmetic of watermark, and analyse whether the scheme is feasibility in 2D Engineering Chart and expectation of the direction and points in future.