Research And Improvement On Robustness Of Digital Watermarking Image

With the rapid development of computer technology and network , digital media iswidely used on Internet.It is difficult for copyright protection because of digital andnetwork characteristics of media information.When the traditional encryption technologycan not meet people's need, digital watermarking technology is used.Digitalwatermarking technology means it is embedded in digital media information, to identifythe copyright, trade data process and legitimate owner.For image, the embeddedwatermark should have good transparency and it doesn't affect the quality of originalimage.After a variety of image processing,it can extract and realize robustness of thewatermarking.At present, the watermarking algorithms are divided into two classes: spacedomain and transform domain Generally speaking, transform domain watermarkingalgorithm is better than space domain watermarking algorithm..Transform domainalgorithms are mainly DFT, DCT, DWT. Wavelet transform has good time domain andfrequency domain characteristics, Its multi-resolution of math microscope propertymakes it is very important in the field of digital watermarking.Wavelet transform hasgood energy and compression characteristics.It is suitable for new image compressioncalled JPEG200.This paper mainly introduce the following two sections:First:An wavelet transform watermarking algorithm based on human visual systemis realized.Binary image is used as watermarking.Use Arnold to scramble it for securityof the watermark.Use wavelet transform to the original image and select intermediatefrequency sub-bands to divide into blocks.Then embed watermarking into suitable blocksaccording to texture factors and brightness factors of image.It can ensure thenon-visibility and robustness.Second: A color blind image watermarking algorithm based on singular valuedecomposition is proposed.Now the images are often color images.It is more practical onresearch based on color images.This paper choose the blue channel toembedwatermarking.The watermark is gray image which has much information.Selectparts of singular value matrices so that it can ensure quality of the image.Experimentsshow that the algorithm has good non-visibility and also good robustness to noise,filtering, compression and various geometric attacks.