How to add slider to figure ? manual thresholding

Hi

I have a an image that I want to add a ui to threshold manually. code below

im = imread('image.png);

for i = 1:rows
    for j = 1:cols

          if(im(i,j) < threshold) 
              out(i,j) = 0;
          elseif(im(i,j) > threshold)
              out(i,j) = 1;
          end
      end
  end

imshow(out);

how do I add a slider that can manually change the threshold in the figure ? help thanks

Answer 1

[Jan]

At first simplyfy your code to the single line - assumed, that you do not want to keep the values of im==threshold:

out = double(im > threshold);

Answer 2

[Image Analyst]

See how I did it in my interactive thresholding app: http://www.mathworks.com/matlabcentral/fileexchange/29372-thresholding-an-image

Basically put down a slider on your GUI. Then in your code, get its value

threshold = get(handles.sldThreshold, 'Value');

Then use that. It would also be nice if you use line() to place a vertical bar over the histogram like I do. This is extremely helpful to the user.