# A Robust and Secure Watermarking Approach Based on Hermite Transform and SVD-DCT
## 7 Conclusions and Future Work  
We presented a robust and invisible hybrid watermark algorithm for digital images in the transformed domain. We proposed a combination of the HT, DCT, and SVD techniques to have more robustness and imperceptibility for the watermarked images. With our proposal, it was possible to use as a watermark both the digital image information (LOGO) and information about the owner (MetaData) and insert them at the same time. In the state-of-the-art, we reported algorithms that use as a watermark only digital images or information about the owner, and their robustness is better because the watermark has less information. Therefore, we integrate different mathematical tools to insert two different watermarks without compromising imperceptibility and robustness. In addition, we included an encryption process to have more security, which could have a thorough performance analysis in future work. With tests and results, we demonstrated that our technique is robust to the majority of attacks used to prove it. The parameters that we considered to apply the attacks, in some cases, were stronger than the parameters employed by other proposals. In Table 4,we present each attack that we applied and its parameters, indicating the value of each metric obtained after applying the algorithm. The results showed that, on the one hand, with _Gaussian_ and _SP_ noises, the _scale_ attack, and _contrast enhancement_, our proposal had excellent performance because, in all cases, the watermark extracted did not have errors and the watermarked image did not present visual modifications. On the other hand, the worst results were obtained when we applied the _rotation_ and _cropping_ attacks, because it was not possible to extract the watermark in some cases. In terms of the comparison with other proposals, as we explained in Section 5.6, our results were better in all cases (Table 6). It is important to note that, despite the fact that some papers [6; 29; 32] reported PSNR values above 60 dB, this factor does not ensure robustness. In our case, all metrics showed that our method was robust, secure, and ensured high imperceptibility, making it suitable for effective copyright protection. As future work, we believe that is necessary to improve the algorithm for the rotation and cropping attacks, because, of all the attacks, only these were the ones that it did not overcome. In addition, we will carry out a thorough analysis of the JST with the ECA for the encryption of the image watermarking, and we will explore a combined watermarking/encryption approach to insert information into a host image and encrypt it in the frequency domain. Conceptualization, S.L.G.-C., E.M.-A., J.B. and A.R.-A. ; methodology, S.L.G.-C., E.M.-A., J.B. and A.R.-A. ; software, S.L.G.-C., E.M.-A. and A.R.-A. ; validation, S.L.G.-C., E.M.-A., J.B. and A.R.-A. ; formal analysis, S.L.G.-C., E.M.-A. and J.B.; investigation, S.L.G.-C., E.M.-A., J.B. and A.R.-A. ; resources, S.L.G.-C., [PERSON]-[PERSON] and J.B.; data curation, S.L.G.-C. and [PERSON]-A.; writing--original draft preparation, [PERSON]-C., [PERSON]-A., J.B. and [PERSON]-A.; writing--review and editing, S.L.G.-C., [PERSON]-A. and J.B.; visualization, S.L.G.-C. and [PERSON]-A.; supervision, S.L.G.-C., [PERSON]-A. and J.B.; project administration, S.L.G.-C. and [PERSON]-A. All authors have read and agreed to the published version of the manuscript. The APC was funded by Instituto Politecnico Nacional and by Universidad Panamericana through the Institutional Program \"Fondo Open Access\" of the Vicerrectoria General de Investigacion. The complete dataset is publicly available on our website: [[https://sites.google.com/up.edu.mx/invico-en/resources/image-dataset-watermarking](https://sites.google.com/up.edu.mx/invico-en/resources/image-dataset-watermarking)]([https://sites.google.com/up.edu.mx/invico-en/resources/image-dataset-watermarking](https://sites.google.com/up.edu.mx/invico-en/resources/image-dataset-watermarking)).