Kamaldeep Joshi and  Rajkumar Yadav and  Ashok Kumar Yadav,  An Additive Watermarking Technique in Gray Scale Images Using Discrete Wavelet Transformation and Its Analysis on Watermark Strength.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    November 2016, vol. 115(7). 1428 - 1433
    [viewed 29 February 2020]. Available from: https://publications.waset.org/pdf/10006131.