Robustness and invisibility are used to evaluate the performance of the watermark algorithm. In order to design a complicated scheme with both preferable robustness and invisibility with low complexity

in this paper

a new watermarking based on Integer DCT scheme is proposed. At first we studied the integral transform characteristic of the frequency coefficients

to find out the coefficients which are fit to be embedded and the relation of theirs embedded threshold. Then we formed a new image by extract each block DC coefficient

and select out numbers of the blocks with complex texture. At last

by Integer DCT

the digital watermark signals were embedded into the frequency coefficients of the theses blocks. Experimental results show that the proposed watermarking scheme ensures that the invisibility of watermark

and have good robustness against various attacks such as JPEG compression

noise

filter and so on

even if under the mosaic attack.