A Blind adaptive watermarking algorithm for hich fidelity of image
图像高逼真度的自适应盲水印算法

A digital watermark is an invisible mark embedded in digital images,video or audio documents,which may be used for a number of different purposes including copyright protection,authentication and captioning. In this paper, an effective adaptive watermarking algorithm for still images is proposed. This is a blind watermarking which can confirm the copyright without original image. The original image is transformed using wavelet transform and the watermark is embedded in selected subband of frequency domain according to neighboring symbol's mean value and odd-even adjugement rule. Experimental results and attack analysis show that the watermark algorithm proposed in this paper can produce the watermarked image which has high fidelity and is robust against some image processing operations, such as JPEG lossy compression,median filtering, additive noise, scaling, and cropping attacks.