Hybrid JND model-guided watermarking method for screen content images

Abstract

With the prevalence of digital products like cellphone, tablet and personal computer, the screen content images (SCIs) consisting of text, graphic, and natural scene picture becomes a significant media in various communication scenarios. In this paper, we propose a novel Spread Transform Dither Modulation (STDM) watermarking scheme based on Hybrid just noticeable distortion model for screen content images. Firstly, the original image was transformed from RGB into YCrCb to ensure stability robustness and invisibility. Then, we proposed a novel automatic classification method based on AC coefficients feature. Different from pictorial block in screen content images, structural-based contrast masking effects was incorporated to adjust the just noticeable distortion value for textual blocks. Finally, the reference image from the SIQAD image database was used to evaluate the performance of our proposed scheme. Experiments showed that our method has a good performance in term of robustness with better visual quality.