To divide an image into 2 equal halves

I wrote the code for it . I can divide the left side of an image and while doing for the right side left part of it is black and right part is the second half of the image . The problem where i am facing is , in the 2nd for loop it starts with k=1 n m=110 so for others column values from 1 to 109 as a default its taking zero. How to sort out this problem.

    % code
x=imread('img1.jpg');
image=rgb2gray(x);
[q r]=size(image);
s=r/2;
for i=1:q
    for j=1:s
        n1(i,j)=image(i,j);
    end
end
for k=1:q
    for m=s:r
        n2(k,m)=image(k,m);
    end
end
imshow(n1)
figure
imshow(n2)
  end

[keerthi]

Thank you walter i got the solution. Can you please explain these two lines.

[Walter Roberson]

Look in the documentation about array indexing.

[Durgesh Naik]

till not working

[Image Analyst]

How do you know? Did you ask keerthi? He accepted the answer so I would assume that it is working.

Answer 1

[Walter Roberson]

n1 = image(:, 1 : end/2);
n2 = image(:, end/2+1 : end );

[Image Analyst]

We also advise keerthi not to use "image" as a variable name because it would destroy the built in function by that name.

[bkshn]

Hello Walter Roberson thanks for your answer. I want to divide my image too, but when I use your solution and use image ,I find an error. m=image(1:170,:); Undefined variable image.

.......

[Image Analyst]

Well . . . what is the name of your variable? I really really doubt it's called image - at least it shouldn't be. So you need to use the actual name of your image array variable. What is it? Let's say it's called grayImage. Then use grayImage(....) instead of image(....)

[Jaya Darshini N K]

i have tried this and this is working perfectly. but images ni and n2 are displaying along with the full image. i want only n1 and n2 to be displayed.

thanks in advance!!!

Answer 2

[Jay Li]

function y = halfpic(x)

% Enter an image in matrix form

n = floor(size(x)/2)

m = size(x);

Lpic = x(:,1:n(2),:);

Rpic = x(:,n(2)+1:m(2),:);

imshow(Lpic);

figure

imshow(Rpic);

[mariena aloor]

How to divide an image in to 8 regions

Answer 3

[JEBA CHRISTILDA]

yes i too tried this but it is showing error in imshow(n1)

[Image Analyst]

That's too bad.

http://www.mathworks.com/matlabcentral/answers/6200-tutorial-how-to-ask-a-question-on-answers-and-get-a-fast-answer