Robust Data Hiding by Hilbert Curve Decomposition

In this paper, a very robust data hiding method is proposed to embed a watermark into a dispersed ordered dithered halftone image by exploiting both the properties of Hilbert curve and dispersed ordered dither matrix. The proposed method hides data by swapping neighboring pixels along Hilbert curve. The experimental results show that the proposed method is very robust. The correct decoding rate is 100% for print/scan, 25% cropping and 25% salt and pepper tampering attacks. Also, the watermarked halftone image has good visual quality because the performance in visual quality by performing two complementary neighboring toggles is better than toggling individual pixels.