X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/canny.git/blobdiff_plain/3d3a92a59f998403d73c474b6565a18b3c248dec..30a1c774eb33c1344a68625e8958dbbd8b996280:/ourapproach.tex?ds=inline

diff --git a/ourapproach.tex b/ourapproach.tex
index 1410d5b..2378139 100644
--- a/ourapproach.tex
+++ b/ourapproach.tex
@@ -272,8 +272,8 @@ $\qquad$ In the ghoul-haunted woodland of Weir.
 The edge detection returns 18,641 and 18,455 pixels when $b$ is
 respectively 7 and 6. These edges are represented in Figure~\ref{fig:edge}.
 When $b$ is 7, it remains one bit per pixel to build the cover vector.
-in this configuration, this leads to a cover vector of size  18,641 and
-36,910 if $b$ is 6.  
+in this configuration, this leads to a cover vector of size  18,641 if b is 7 
+and 36,910 if $b$ is 6.  
 
 \begin{figure}[t]
   \begin{center}
@@ -304,10 +304,16 @@ in this configuration, this leads to a cover vector of size  18,641 and
 
 The STC algorithm is optimized when the rate between message length and 
 cover vector length is less than 1/2. 
-So, only 9,320 bits (resp. 18,455 bits) are available for embedding 
-in the former configuration where $b$ is 7 (resp. where $b$ is 6).
-In the first cases, about the third part of the poem is hidden into the cover
-whereas the latter allows to embed more than the half part of it. 
+So, only 9,320 bits  are available for embedding 
+in the  configuration where $b$ is 7.
+
+When $b$ is 6, we could have considered 18,455 bits for the message.
+However, first experiments have shown that modifying this number of bits is too 
+easily detectable. 
+So, we choose to modify the same amount of bits (9,320) and keep STC optimizing
+which bits to change among  the 36,910 bits.
+
+In the two cases, about the third part of the poem is hidden into the cover. 
 Results with \emph{adaptive+STC} strategy are presented in 
 Fig.~\ref{fig:lenastego}.
 
