From: couturie Date: Sun, 13 Jan 2013 19:26:28 +0000 (+0100) Subject: qlq coquilles (mais j'ai plus regardé le fond) X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/canny.git/commitdiff_plain/b1b65804c7c985c998293a21318b5f68e51159e3?ds=sidebyside;hp=--cc qlq coquilles (mais j'ai plus regardé le fond) --- b1b65804c7c985c998293a21318b5f68e51159e3 diff --git a/experiments.tex b/experiments.tex index cd2ed1a..e4db410 100644 --- a/experiments.tex +++ b/experiments.tex @@ -58,7 +58,7 @@ wPSNR & 86.43& 77.47 \\ Let us compare the STABYLO approach with other edge based steganography schemes with respect to the image quality. -Fist off all, wPSNR and PSNR of the Edge Adaptive +First of all, wPSNR and PSNR of the Edge Adaptive scheme detailed in~\cite{Luo:2010:EAI:1824719.1824720} are lower than ours. Next both the approaches~\cite{DBLP:journals/eswa/ChenCL10,Chang20101286} focus on increasing the payload while the PSNR is acceptable, but do not diff --git a/intro.tex b/intro.tex index f69d926..18ea7ab 100644 --- a/intro.tex +++ b/intro.tex @@ -1,8 +1,8 @@ -This work considers digital images as covers and foundation is +This work considers digital images as covers and it is based on spatial least significant-bit (LSB) replacement. In this data hiding scheme a subset of all the LSB of the cover image is modified -with a secret bit stream depending on to a key, the cover, and the message to embed. +with a secret bit stream depending on a key, the cover, and the message to embed. This well studied steganographic approach never decreases (resp. increases) pixel with even value (resp. odd value) and may break structural symmetry. These structural modification can be detected by statistical approaches @@ -56,7 +56,7 @@ There remains a large place between random selection of LSB and feature based mo We argue that modifying edge pixels is an acceptable compromise. Edges form the outline of an object: they are the boundary between overlapping objects or between an object and the background. A small modification of pixel value in the stego image should not be harmful to the image quality: -in cover image, edge pixels already break its continuity and thus already contains large variation with neighbouring +in cover image, edge pixels already break its continuity and thus already contain large variation with neighbouring pixels. In other words, minor changes in regular area are more dramatic than larger modifications in edge ones. Our proposal is thus to embed message bits into edge shapes while preserving other smooth regions. diff --git a/stc.tex b/stc.tex index 7ce100b..16fbfb3 100644 --- a/stc.tex +++ b/stc.tex @@ -63,7 +63,7 @@ that minimizes $D_X(x,y)$ has exponential complexity with respect to $n$. The Syndrome-Trellis Codes (STC) presented by Filler et al. in~\cite{DBLP:conf/mediaforensics/FillerJF10} is a practical solution to this complexity. Thanks to this contribution, -the solving algorithm has a linear complexity with resspect to $n$. +the solving algorithm has a linear complexity with respect to $n$. First of all, Filler et al. compute the matrix $H$ by placing a small sub-matrix $\hat{H}$ of size $h × w$ next