MATLAB: Image processing using chaotic map

chaotic tent mapimage processing

The chaotic tent map is given by:
xi+1 = f (xi,μ)
(f (xi,μ)= μxi, if xi < 0.5
μ(1−xi), otherwise;) ……………… Eq.1
where xi ∈[ 0,1], for i ≥ 0. This map transforms an interval [0, 1] onto itself and contains only one control parameter μ, respectively, where μ ∈[ 0,2].
Steps:
(1) Read plain-images (original image) (Ma×b), get size of M, e.g., use [a, b, c] to save the size of M, a = 256, b = 256, c = 3, let N = a∗b∗c, and initiate control parameter (μ) of the chaotic tent map.
(2) Input the secret (encryption) key x0 into the algorithm. Iterate the chaotic tent map N times using equation 1, and obtain the key array x(n), the size of x(n) is N;
(3) Encrypt each element of matrix (Ma×b) using the key array x(n), that is, mix the original image M(a×b) components with the key array x(n);
(4) The resulting image of step (3) is the ciphered image.
Coding:
M=imread('cameraman.tif');
[a,b] = size(M);
N=a*b;
u=1.999;
x(1)=0.5;
for i=1:N
        if x(i) < 0.5 %and condition
            x(i+1)=u*x(i); %is it right

        else
            if x(i) >= 0.5 %and this condition 
            x(i+1)=u*(1-x(i)); %is it right
            end
        end
    end
r=xor(x(i+1),M);
I wrote this code by following the steps mentioned above(research paper attached). I also attached the required output but i am getting a full white or full black image. Can someone help me identify the problem.

Best Answer

Your final r is a scalar double. You will not get much from it.
Your x will be a vector double. You would need to reshape it and uint8 it.
Related Question