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 porposed.This is a blind watermark confirming the copyright without the original image

which is transformed using wavelet transform

and the watermark is embedded in the selected subband of frequency domain according to neighboring symbol’s mean value and odd-even adjugement rule. The experimental results and attack analysis show that the watermark algorithm is transparent and robust against some image processing operations

such as JPEG lossy compression

median filtering

additive noise

scaling

and incorporating attacks.