+account the Human Visual System (HVS).
+The other ones have been designed to tackle this problem.
+
+If we apply them on the running example,
+the PSNR, PSNR-HVS-M, and wPSNR values are respectively equal to
+68.39, 79.85, and 89.71 for the stego Lena when $b$ is equal to 7.
+If $b$ is 6, these values are respectively equal to
+65.43, 77.2, and 89.35.
+
+
+
+
+\begin{table*}
+\begin{center}
+\begin{tabular}{|c|c|c||c|c|c|c|c|c|}
+\hline
+Schemes & \multicolumn{4}{|c|}{STABYLO} & \multicolumn{2}{|c|}{HUGO}& \multicolumn{2}{|c|}{EAISLSBMR} \\
+\hline
+Embedding & Fixed & \multicolumn{3}{|c|}{Adaptive (about 6.35\%)} & \multicolumn{2}{|c|}{Fixed}& \multicolumn{2}{|c|}{Fixed} \\
+\hline
+Rate & 10\% & + sample & +STC(7) & +STC(6) & 10\%&6.35\%& 10\%&6.35\%\\
+\hline
+PSNR & 61.86 & 63.48 & 66.55 (\textbf{-0.8\%}) & 63.7 & 64.65 & {67.08} & 60.8 & 62.9\\
+\hline
+PSNR-HVS-M & 72.9 & 75.39 & 78.6 (\textbf{-0.8\%}) & 75.5 & 76.67 & {79.23} & 71.8 & 74.3\\
+%\hline
+%BIQI & 28.3 & 28.28 & 28.4 & 28.28 & 28.28 & 28.2 & 28.2\\
+\hline
+wPSNR & 77.47 & 80.59 & 86.43(\textbf{-1.6\%})& 86.28 & 83.03 & {87.8} & 76.7 & 80.6\\
+\hline
+\end{tabular}
+
+\begin{footnotesize}
+\vspace{2em}
+Variances given in bold font express the quality differences between
+HUGO and STABYLO with STC+adaptive parameters.
+\end{footnotesize}
+
+\end{center}
+\caption{Quality measures of steganography approaches\label{table:quality}}
+\end{table*}
+
+
+
+Results are summarized in Table~\ref{table:quality}.
+Let us give an interpretation of these experiments.
+First of all, the adaptive strategy produces images with lower distortion
+than the images resulting from the 10\% fixed strategy.
+Numerical results are indeed always greater for the former strategy than
+for the latter one.
+These results are not surprising since the adaptive strategy aims at
+embedding messages whose length is decided according to an higher threshold
+into the edge detection.
+Let us focus on the quality of HUGO images: with a given fixed
+embedding rate (10\%),
+HUGO always produces images whose quality is higher than the STABYLO's one.
+However our approach is always better than EAISLSBMR since this one may modify
+the two least significant bits.
+
+If we combine \emph{adaptive} and \emph{STC} strategies
+(which leads to an average embedding rate equal to 6.35\%)
+our approach provides metrics equivalent to those provided by HUGO.
+In this column STC(7) stands for embedding data in the LSB whereas
+in STC(6), data are hidden in the last two significant bits.
+
+
+
+The quality variance between HUGO and STABYLO for these parameters
+is given in bold font. It is always close to 1\% which confirms
+the objective presented in the motivations:
+providing an efficient steganography approach with a lightweight manner.
+
+
+Let us now compare the STABYLO approach with other edge based steganography
+approaches, namely~\cite{DBLP:journals/eswa/ChenCL10,Chang20101286}.
+These two schemes focus on increasing the
+payload while the PSNR is acceptable, but do not
+give quality metrics for fixed embedding rates from a large base of images.
+
+
+
+
+\subsection{Steganalysis}\label{sub:steg}
+
+
+
+The steganalysis quality of our approach has been evaluated through the % two
+% AUMP~\cite{Fillatre:2012:ASL:2333143.2333587}
+% and
+Ensemble Classifier~\cite{DBLP:journals/tifs/KodovskyFH12} based steganalyser.
+This approach aims at detecting hidden bits in grayscale natural
+images and is
+considered as state of the art steganalysers in the spatial domain~\cite{FK12}.
+%The former approach is based on a simplified parametric model of natural images.
+% Parameters are firstly estimated and an adaptive Asymptotically Uniformly Most Powerful
+% (AUMP) test is designed (theoretically and practically), to check whether
+% an image has stego content or not.
+% This approach is dedicated to verify whether LSB has been modified or not.
+% , the authors show that the
+% machine learning step, which is often
+% implemented as a support vector machine,
+% can be favorably executed thanks to an ensemble classifier.
