Extraction of blood vessel using entropic thresholding

hello sir m working with extraction of blood vessels..i want to extract the blood vessels using entropic thresholding method .I also have a code..but when i execute it i get a plain blank image i tried varying the values but still its the same.can somebody please help me on this..please?

Heres my entire code

    function GABOR_Callback(hObject, eventdata, handles)
  % hObject    handle to GABOR (see GCBO)
  % eventdata  reserved - to be defined in a future version of MATLAB
  % handles    structure with handles and user data (see GUIDATA)
  A = getimage();
  I = A(:,:,2);
  %A(:,:,1) =0;
  %A(:,:,3) =0;
  N = 12;
  Sx = 8;
  Sy = 2;
  f = 0.1;
  nf = 1;
  theta = 0;
  I = im2double(I);
  img_out = zeros(size(I,1),size(I,2),N);
  for i = 1:12
          theta = (i*15*pi)/180;
      for x = -fix(Sx):fix(Sx)
          for y = -fix(Sy):fix(Sy)
          xPrime = x * cos(theta) + y * sin(theta);
          yPrime = y * cos(theta) - x * sin(theta);
          G(fix(Sx)+x+1,fix(Sy)+y+1) = exp(-nf*pi*((xPrime/Sx)^2+(yPrime/Sy)^2))*cos(2*pi*f*xPrime);
          end
      end
     %G = max(G(:))-G;
     %s=sum(G(:));
     %mn=s/357;
     %G=G-mn;
     %figure;
     %imshow(real(G));
     %title('real image');
     c = conv2(I,real(G),'same');
     %figure;
     %imshow(c);
     %title('convo image');
     img_out=zeros(size(c,1),size(c,2),N);
     img_out(:,:,i)= c;
     image3D = cat(3,img_out(:,:,1),img_out(:,:,2), img_out(:,:,3),img_out(:,:,4),img_out(:,:,5), img_out(:,:,6),img_out(:,:,7),img_out(:,:,8), img_out(:,:,9),img_out(:,:,10),img_out(:,:,11),img_out(:,:,12));
     % Find the max along dimension #3.
     maxG = max(image3D, [], 3);
  end
   figure;
   imshow(maxG);
   title('convoluted image');

      rt = fix(maxG);

      [M,N] =size(rt);
      cmtx = zeros(256,256);
      for m = 1:M-1           
           for n = 1:N-1            
            cmtx(rt(m,n)+1,rt(m,n+1)+1) = cmtx(rt(m,n)+1,rt(m+1,n+1)+1) + 1;    
      end
  end

      scmtx = sum(cmtx(:));    
       prob = cmtx/scmtx;    

emax = -100;  
for i=1:255

      probA = 0;
      probC = 0;

      subProbA = prob(1:i,1:i);
      probA = sum(subProbA(:));
      HA(i) = -0.5*(probA*log2(probA+0.0000001));

      subProbC = prob(i+1:256,i+1:256);
      probC = sum(subProbC(:));
      HC(i) = -0.5*(probC*log2(probC+0.0000001));

      e1(i) = HA(i) + HC(i); 
      if e1(i) >= emax
          emax = e1(i);
          tt1 = i;
      end
  end
  figure;
  imshow(e1(i));

and my image for thresholding is (this image is the output of convolution)

/matlabcentral/answers/uploaded_files/4958/mor.jpg

%

[Image Analyst]

I'll fix it for you again, but please read this http://www.mathworks.com/matlabcentral/answers/13205-tutorial-how-to-format-your-question-with-markup

[Image Analyst]

Well you edited and messed up all the nice formatting I did for you! Did you read the link I gave you?

Tip: Paste your code into a MATLAB editor window, type control-a, then control-i, then control-c and come back here and type control-v to paste in the fixed code. Then highlight all the code and click {}Code.

I'll try to look at your code tomorrow.

[vidya]

sir m extremly sorry...i did not mean to mess up your code...sorry i was in hurry.its my mistake..but sir please do look into my code and help me please

[Image Analyst]

There's some problem:

Attempted to access cmtx(2.51537,4.48218); index must be a positive integer or logical.
Error in test (line 60)
       cmtx(rt(m,n)+1,rt(m,n+1)+1) = cmtx(rt(m,n)+1,rt(m+1,n+1)+1) + 1;

I didn't dig into the code, I just ran it. But you can't have fractional indexes - they must be integers, like row 2, column 4. There is no 2.51537th row or 4.48218th column.

[vidya]

right sir ..i edited the above code..i fixed this error using rt = fix(maxG) i donno whether m right by doing this

[Image Analyst]

I don't know what you did, but if you fixed it, then you are doing the right thing.

[Priya Natarajan]

since the values are in double try converting the output to uint8 im2uint8(image) or use mat2gray(image).

Answer 1

[Image Analyst]

Evidently no pixels are above your threshold. What is the threshold that your code chose?

[vidya]

Sir i changed my code..can u now suggest me what is the problem..is there any mistake in my code please

[Image Analyst]

What you posted seems to start past the beginning of your code. Please attach your m-file.

[vidya]

sir i have pasted my m-file code