I have plotted a image using imshow(Image). Now I placed "hold on" command. I have drawn the boundaries of each object in the image as given in code below. How can I capture the new image with boundaries drawn in the plot into an array of pixels ??

[B,L,N] = bwboundaries(Image);

imshow(Image); hold on;

for k=1:length(B),

    boundary = B{k};
    if(k > N)
        plot(boundary(:,2),boundary(:,1),'g','LineWidth',2);
    else
        plot(boundary(:,2),boundary(:,1),'r','LineWidth',2);
    end
end

Answer 1

[Image Analyst]

Just assign them to an image in a loop inside the loop:

for k=1:length(B)
    boundary = B{k};
    for k = 1 : size(boundary, 1)
        x = boundary(:,2); % Column
        y = boundary(:,1); % Row
        boundaryImage(y, x) = 255;
    end
end

[Bhuvanesh]

Actually your idea helped me a lot . There is a slight change which is to be applied if only boundary is to be colored:-

Instead of

x = boundary(:,2); % Column

y = boundary(:,1); % Row

It should be :-

x = boundary(k,2); % Column

y = boundary(k,1); % Row

Thanks a lot :)