Guo, J.-M., and S. Seshathiri. “Watermarking in Dot-Diffusion Halftones Using Adaptive Class-Matrix and Error Diffusion”. ECTI Transactions on Computer and Information Technology (ECTI-CIT), vol. 13, no. 1, June 2019, pp. 1-8, doi:10.37936/ecti-cit.2019131.189387.