In their algorithm, the image has been split into two component images. Each component image has a pair of pixels for every pixel in the original image. These pixel pairs are shaded black or white according to the following rule: if the original image pixel was black, the pixel pairs in the component images must be complementary; randomly shade one ■□, and the other □■. When these complementary pairs are overlapped, they will appear dark gray. On the other hand, if the original image pixel was white, the pixel pairs in the component images must match: both ■□ or both □■. When these matching pairs are overlapped, they will appear light gray.
What I would like to do is play around with text watermarking and use text instead of the image! So for images, you can consider pixel values similarly for text what can I consider and how can I similar idea (Algorithm) to the piece of text?