Digital Watermarking on Recolored Images for Protanopia

most women with any of the various form of dichromacy are protanopia type, i.e. red color blindness. They cannot see red shades in color images the same way as non-color blind people. To improve the perception of all objects within the images, image recoloring techniques are implemented. However, when digital watermarking is applied on the recolored images, the embedded watermark will affect its pixel values, and lead to some distortions in color shades within the images. This paper thus proposes a watermarking method in images recolored for people with protanopia, so that the watermarked recolored image can be applicable to people with protanopia as the original recolored image. In the proposed method, Long wavelengths (L) component of the LMS color space of a recolored image is used for watermark embedding. To extract the watermark, the original version of un-watermarked L component is estimated, and subtracted from the watermarked one. The experiments show promising results obtained from our proposed method compared to the previous method under various attacks.