X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/canny.git/blobdiff_plain/b32ae50ac6a1fa30903bce7ee91e6e42c13ed3c6..bd2fce977129b24b117509715dada6f0c0a0f98a:/intro.tex?ds=inline

diff --git a/intro.tex b/intro.tex
index cd2aeea..5fa4b70 100644
--- a/intro.tex
+++ b/intro.tex
@@ -16,7 +16,7 @@ steganalysis methods~\cite{DBLP:journals/tsp/DumitrescuWW03,DBLP:conf/mmsec/Frid
 
 Let us recall too that this drawback 
 can be fixed by considering the LSB matching (LSBM) subcategory, in which
-the $+1$ or $-1$ is randomly added to the cover pixel's LSB value 
+a $+1$ or $-1$ is randomly added to the cover pixel's LSB value 
 only if this one does not correspond to the secret bit.
 %TODO : modifier ceci
 By considering well-encrypted hidden messages, the probabilities of increasing or decreasing the value of pixels  are equal. Then usual statistical approaches 
@@ -60,15 +60,13 @@ The features embedded in WOW and UNIWARD are based on Wavelet-based
 directional filter. Thus, similarly, the distortion function is 
 the sum  of the differences between these wavelet coefficients  
 computed from the cover and from the stego images.
-
-
 Due to this distortion measures, HUGO, WOW and UNIWARD allow
 to embed messages that are $7$ times longer than the former
 ones with the same level of 
 indetectability as LSB matching. 
 However, this improvement has a larger computation cost, mainly due to
  the distortion function
-calculus. 
+computation.
 
 
 There remains a large place between random selection of LSB and feature based modification of pixel values.
@@ -113,7 +111,7 @@ For instance, studied payloads range from 0.04 to 0.4 modified bits per pixel.
 Contrarily, we argue that some images should not be taken 
 as a cover because of the nature of their signals.
 Consider for instance a uniformly black image: a very tiny modification of its 
-pixels can be easily detectable.
+pixels can be easily detected.
 Practically speaking, if Alice would send
 a hidden message to Bob, she would never consider
 such kind of image and a high embedding rate.   
@@ -143,11 +141,11 @@ even in the worst case scenario, the attacker
 will not be able to obtain the original message content.
 Doing so makes our steganographic protocol, to a certain extend, an asymmetric one.
 
-To sum up, in this research work, well-studied and experimented
+To sum up, well-studied and experimented
 techniques of signal processing (adaptive edges detection), 
 coding theory (syndrome-trellis codes), and cryptography 
-(Blum-Goldwasser encryption protocol) are combined 
-to compute an efficient steganographic
+(Blum-Goldwasser encryption protocol) are combined in this research work.
+The objective is to  compute an efficient steganographic
 scheme, whose principal characteristic is to take into 
 consideration the cover image and to be compatible with small computation resources.