# Improving DFT-Based Image Watermarking Using Particle Swarm Optimization Algorithm
## 6 Conclusions
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \multirow{2}{*}{**Method**} & \multirow{2}{*}{\begin{tabular}{c} **JPEG** \\ **Compression** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Watermark** \\ **Payload** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Imperceptibility** \\ **Metric Used in** \\ **PSO Fitness** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Detection** \\ **Metric Used in** \\ **PSO Fitness** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Maximum** \\ **Number of** \\ **Iterations** \\ **in PSO** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Number of Images** \\ **in Trials/Bit Depth** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Geometric Attacks** \\ **of Noises** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **Types** \\ **of Noises** \\ \end{tabular} } \\ \hline
[19] & 10–100 & 1024 bits & PSNR & BER & 30 & 8 images in & & \
\begin{tabular}{c} Gaussian, Salt \\ grayscale with \\ 8 bit/pixel in depth \\ \end{tabular} & Resizing. Cropping &
\begin{tabular}{c} Gaussian, Salt \\ and pepper, \\ Speckle \\ \end{tabular} \\ \hline
[20] & 20–100 & 4096 bits & \begin{tabular}{c} PSNR-Mean \\ SSIM \\ \end{tabular} & BER & 30 & 64 images in color & & \
\begin{tabular}{c} Gaussian, Salt \\ with 24 bit/pixel \\ in depth \\ \end{tabular} & Cropping &
\begin{tabular}{c} Gaussian, Salt \\ and pepper, \\ Speckle \\ \end{tabular} \\ \hline
[21] & 30–100 & 1024 bits & PSNR & \begin{tabular}{c} Normalized (NC) \\ and Cross (CC) \\ Correlations \\ \end{tabular} & 10 & \
\begin{tabular}{c} 10 images in \\ grayscale with \\ 8 bit/pixel in depth \\ \end{tabular} & Cropping &
\begin{tabular}{c} Gaussian, Salt \\ and pepper \\ and pepper \\ \end{tabular} \\ \hline
[22] & 10–100 & 16,384 bits & PSNR & NC & 100 & \
\begin{tabular}{c} 8 images in \\ grayscale with \\ 8 bit/pixel in depth \\ \end{tabular} & Rotation, Resizing, &
\begin{tabular}{c} Gaussian, Salt \\ and pepper \\ Speckle \\ \end{tabular} \\ \hline
[24] & 10–100 & 16384 bits & - & \begin{tabular}{c} 2D Correlation \\ Coefficient \\ \end{tabular} & 10 & \
\begin{tabular}{c} 12 image in \\ grayscale with \\ 8 bit/pixel in depth \\ \end{tabular} & Rotation, Scaling &
\begin{tabular}{c} Gaussian \\ and pepper, \\ Speckle \\ \end{tabular} \\ \hline
[25] & 75–100 & 1024 bits & PSNR & NC & - & \
\begin{tabular}{c} 2 images in \\ grayscale with \\ 8 bit/pixel in depth \\ \end{tabular} & Cropping &
[26] & 70–100 & 1024 bits & PSNR & NC & 100 & \begin{tabular}{c} 4 images in \\ grayscale with \\ 8 bit/pixel in depth \\ \end{tabular} & Rotation, Cropping & \begin{tabular}{c} Gaussian, Salt \\ and pepper, \\ Speckle \\ \end{tabular} \\ \hline Proposed Method & 20–100 & 32 bits & VIF & BCR & 100 & \
\begin{tabular}{c} 100 images in \\ color with \\ 24 bit/pixel \\ in depth \\ \end{tabular} &
\begin{tabular}{c} Rotation, Resizing, \\ Cropping, Affine \\ transformation, \\ Thearsation, \\ Thearsing, Aspect \\ ratio changes \\ \end{tabular} \\ \hline \end{tabular}
\end{table} 
Table 10: Performance comparison. each image in a given dataset, moreover it has benefits in terms of imperceptibility and robustness. As a future work, we will try improving the payload of our proposal, keeping the imperceptibility and robustness obtained hitherto. Conceptualization, M.C.-H. and A.C.-H.; Funding acquisition, F.J.G.-U. ; Methodology, M.C.-H., A.C.-H. and F.J.G.-U. ; Software, M.C.-H. and A.C.-H.; Supervision, M.C.-H.; Validation, M.C.-H.; Writing--original draft, M.C.-H.; Writing--review and editing, A.C.-H. and F.J.G.-U. All authors have read and agreed to the published version of the manuscript. This research was funded by Consejo Nacional de Ciencia y Tecnologia de Mexico (CONACYT) grant number 161591, Instituto Politecnico Nacional (IPN) grant number SIP20210582 And The APC was funded by PAPIIT IT-101119 project research from DGAPA in the Universidad Nacional Autonoma de Mexico (UNAM). Not applicable. No new data were created or analyzed in this study.