A novel fragile watermark applying in verification

In this paper a novel fragile watermark is proposed. The watermark is embedded into a grayscale image in frequency domain. We use permuted watermark to generate address codes, then find the corresponding position in host image blocks and change the coefficient value of neighboring pixels according to a chaotic pseudo-random sequence. This method succeeds in the transformation of the watermark information from individual pixel to a group of pixels that forms relative address, hence greatly reduces the number of changed coefficients and obtains a high peak signal-to-noise ratio (PSNR) as expected. Our simulation results show the effectiveness and sensitivity of this technique.