--- a/writeup/techreport.tex	Mon May 03 01:07:21 2010 -0400
+++ b/writeup/techreport.tex	Mon May 03 18:38:27 2010 -0400
@@ -162,6 +162,15 @@
 This filter has a probability of not being applied, at all, of 60\%.
 
 
+\subsection{Pixel permutation}
+
+This filter permuts neighbouring pixels. It selects first $\frac{complexity}{3}$ pixels randomly in the image. Each of them are then sequentially
+exchanged to one other pixel in its $V4$ neighbourhood. Number of exchanges to the left, right, top, bottom are equal or does not differ from more than 1
+if the number of selected pixel is not a multiple of 4. 
+
+It has has a probability of not being applied, at all, of 80\%.
+
+
 \subsection{Distorsion gauss}
 
 This filter simply adds, to each pixel of the image independently, a gaussian noise of mean $0$ and standard deviation $\frac{complexity}{10}$.