what is the meaning of the following code ?
2 views (last 30 days)
Show older comments
Following code is for retrieving image from stego image in image steganography. Can anyone please tell me meaning of it ?
function Retrive_Callback(hObject, eventdata, handles)
global l;
h=mod(l,2);
p=zeros(1000,1000);
for x=1:1000
for y=1:1000
if(h(x,y)==1)
p(x,y)=255;
end
end
end
s=im2bw(p);
axes(handles.axes4);
imshow(s);
grid on;
0 Comments
Accepted Answer
Sebastian Körner
on 18 Sep 2019
the code semes to have some errors in it but i think the idea of your code is :
create a 1000x1000 matrix with zeros, replacing some zeros with 255 (all values in a line from top left corner to bottom right corner of the matrix)
format the matrix to a image and show the image
More Answers (1)
Image Analyst
on 2 Oct 2019
p is just 255 * h. And s just thresholds p back to 0 or 1, which is just the original h. So all that code is unnecessary.
Replace with
function Retrive_Callback(hObject, eventdata, handles)
global l;
h=mod(l,2);
axes(handles.axes4);
imshow(h, []);
grid on;
By the way, you reversed x and y. Matrices are indexed (y, x) NOT (x,y) because the first index is the y, or row, value, not the column value.
See Also
Categories
Find more on Read, Write, and Modify Image in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!