help me to solve error in integer coding

i dont know why have error in this coding. please help me to solve it

Error using ./ Integers can only be combined with integers of the same class, or scalar doubles.

Error in try1 (line 21) imgN=double(img-min(img(:)))/(max(img(:)-min(img(:))));

%# read image
    img = imread('C:\Users\User\Pictures\N2.jpg');
    %# normalize to 0...1
    imgN = double(img-min(img(:)))/(max(img(:)-min(img(:))));
    th1=graythresh(imgN);
    th2 = graythresh(imgN(imgN>th1));

      cellMsk = imgN>th1;
      nucMsk = imgN>th2;

      figure,imshow(cellMsk+nucMsk,[])

Answer 1

[Geoff Hayes]

izayn - the problem in the line

 imgN = double(img-min(img(:)))/(max(img(:)-min(img(:))));

is that the

 double(img-min(img(:)))

is a multi-dimensional array (the same size as your matrix) and is of class/type double. The

 (max(img(:)-min(img(:))))

will be a scalar of class/type that is the same as your image. I get the same error if I read an image where each element is a 8-bit unsigned integer. To get around this problem, just cast the right half of the equation to be of double type too. Your equation then becomes

 imgN = double(img-min(img(:)))/double(max(img(:)-min(img(:))));

Try the above and see what happens!

[izyan hanum]

please run this code and there are error at filtImg = conv2(imgN,gf,'same');

 %# read image
      img = imread('C:\Users\User\Pictures\N2.jpg');
      %# normalize to 0...1
     % imgN = double(img-min(img(:)))/(max(img(:)-min(img(:))));
      imgN = double(img-min(img(:)))/double(max(img(:)-min(img(:))));
      th1=graythresh(imgN);
      th2 = graythresh(imgN(imgN>th1));

      cellMsk = imgN>th1;
      nucMsk = imgN>th2;

      figure,imshow(cellMsk+nucMsk,[])

     % (2) Smooth the raw image (to avoid over-segmentation) and impose nuclei as minima

      [xx,yy]=ndgrid(-5:5,-5:5);
      gf = exp((-xx.^2-yy.^2)/20);
      filtImg = conv2(imgN,gf,'same');

      figure,imshow(filtImg,[])

      filtImgM = imimposemin(-filtImg,nucMsk);

     % (3) Watershed, mask cells, and display

      ws = watershed(filtImgM);
      ws(~cellMsk) = 0;

      lblImg = bwlabel(ws);

      figure,imshow(label2rgb(lblImg,'jet','k','shuffle'));

[izyan hanum]

picture below

[Geoff Hayes]

izayn - if you are observing an error, please post it.