A Hybrid Reversible Image Watermarking Technique based on Fractal Encryption and Grey Wolf Optimization
H. R. Lakshmi, Surekha Borra · 2021 IEEE Mysore Sub Section International Conference (MysuruCon) · 2021
To improve robustness and imperceptibility of watermark, a new hybrid image reversible watermarking technique is proposed in the research paper on the basis of fractal encryption and Modified Quadratic Difference Expansion (MQDE). At first, fractal encryption with L shaped tromino theorem is applied to the watermark (secret image) for improving the security of data transmission with limited system complexity. Further, Grey Wolf Optimization (GWO) is used for optimizing the block assignment to imbibe the secret image into cover (host) image that significantly improves the visibility. Finally, MQDE technique is used for improving the embedding rate and visual quality of watermarking. Experimental metrics validate proposed technique is superior to existing models in light of robustness against noise, cropping attacks, rotation and histogram equalization. It also shows satisfactory imperceptibility. The proposed model retrieves the original cover and secret image without losing the essential information and delivers optimum security.