The copyright protection of multimedia information is more and more important in the digital age, digital watermarking is a solution to address the topic. This paper proposes a new robust image watermarking scheme based on discrete ridgelet transform (DRT) and discrete wavelet transform (DWT). The scheme respectively embeds a copy of color image watermark into DWT domain and DRT domain, and uses a conception of semi-watermark. Experiment results demonstrate that the watermark can resist various attacks such as adding Gaussian or Union Distribution Noise, JPEG compression, brightness adjustment, contrast adjustment, altering color balance, lens blur, zooming in or out, cropping and some combined attacks etc.

Gives a new control method, which is used in the AGC systems of cold rolling mill. TO the shortage of control method which is used now, analyses and synthesize dynamic mathematical model of AGC, presents a new method: μ method. Simulations of experiment indicate that the μ control method has good system performance and robust stability performance.