WHEN I AM EXECUTING THIS CODE I GET A JULIA IMAGE .HOW CAN I READ THIS IMAGE IN THE CODE AND USE THIS TO GENERATE KEY FOR ENCRYPTION CRYPTION

x = linspace(-1.3,1.3,501);
y = linspace(-1.3,1.3,501);
[X,Y] = meshgrid(x,y);
C = ones(size(X))*(0.360284+0.100376*1i);
Z_max = 1e6; it_max = 50;
Z = complex(X,Y);
B = zeros(size(C));
for k = 1:it_max
    Z = Z.^2 + C;
    B = B + (abs(Z)<2);
end
% only show those bounded points
imagesc(B);
colormap(jet);
title('Julia Set "Dragon" for $c=0.360284+0.100376i$','FontSize',16,'interpreter','latex');
axis off                                  

When i am running this i am getting "B does not exist"

I=imread('B.extenstion'); 
imshow(I) 
title('Input Image')
I1=rgb2gray(I);
figure,imshow(I1) 
title('gray converted Image')

[Walter Roberson]

you do not write B to an image file so you cannot read it from the file

[Walter Roberson]

Due to the laws of the United States, we cannot discuss encryption techniques.

[sabitri]

How can i get B as a image and read it? @Walter Roberson

Answer 1

[Walter Roberson]

Bre = im2uint8(rescale(B));
imgfile = 'B.png';
cmap = jet;
Bc = ind2rgb(Bre, cmap) ;
imwrite(Bc, imgfile)

I = imread(imgfile);

I and Bc should be exactly the same after this.

Answer 2

[Image Analyst]

Evidently "B.extenstion" does not exist. Maybe you wanted extenstion to be png or tif or something. Try this:

fileName = fullfile(pwd, 'B.png'); % or whatever the actual extension is.
if ~isfile(fileName)
    errorMessage = sprintf('ERROR: this file does not exist:\n%s', fileName);
    uiwait(errordlg(errorMessage));
    return;
end
% Else the file does exist.
I = imread(fileName);

[Walter Roberson]

User asked how to save array B as an image file and then read the file.

[Image Analyst]

They did not explicitly ask how to save B, and I assume they were able to save it. They did however ask how to read the file back from disk and got an error about the file not existing. I assume they saved it with a name other than 'B.extenstion'. I actually did not add much (they already knew they had to use imread) -- I just basically threw up a friendlier error message if they got the filename wrong.

[Walter Roberson]

"How can i get B as a image and read it?"

Reading B as an image requires saving it as an image.

With the imagesc and jet colormap I would not assume that they know how to save the array as an image.