Digital image watermarking against photo to cartoon effects

Abstract

This paper presents an image watermarking method against photo to cartoon effects based on the modification of reflectance component of a host color image. In the embedding process, the reflectance component of the saturation color component in HSV color space of a host image is used to convey a same size binary watermark. In the extraction process, each embedded bit is blindly extracted by subtracting the predicted original reflectance component from the watermarked one. The quality of watermarked image is evaluated by weighted peak signal-to-noise ratio (wPSNR), while the accuracy of extracted watermark is evaluated by normalized correlation (NC). The performance of the proposed method is evaluated and compared with the previous watermarking method. The results show improvement in terms of NC at comparable wPSNR under various types of photo to cartoon effects.