I have written a logic for co-occurance matrix but it is taking a lot of time, is there any other to built the logic?

Question

teja jayavarapu 2018-2-6

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/380964-i-have-written-a-logic-for-co-occurance-matrix-but-it-is-taking-a-lot-of-time-is-there-any-other-to

评论： teja jayavarapu 2018-2-15

4.Calculate four co-occurrence matrices P, take the distance 1, the angles are 0, 45, 90, 135 respectively

%M&N ARE ROWS &COLOUMNS OF THE IMAGE
%-------------------------------------------------------------------------- 
P = zeros(16,16,4);   %Generate 4 16 * 16 0 matrix
for m = 1:16 
      for n = 1:16 
          for i = 1:M 
              for j = 1:N 
                  if 
  j<N&Gray(i,j)==m-1&Gray(i,j+1)==n-1  %0 ° m for the row n for the column
                      P(m,n,1) = P(m,n,1)+1; 
                      P(n,m,1) = P(m,n,1); 
                  end 
                  if i>1&j<N&Gray(i,j)==m-1&Gray(i-1,j+1)==n-1  %45° 
                      P(m,n,2) = P(m,n,2)+1; 
                      P(n,m,2) = P(m,n,2); 
                  end 
                  if i<M&Gray(i,j)==m-1&Gray(i+1,j)==n-1  %90° 
                      P(m,n,3) = P(m,n,3)+1; 
                      P(n,m,3) = P(m,n,3); 
                  end 
                  if i<M&j<N&Gray(i,j)==m-1&Gray(i+1,j+1)==n-1  %135° 
                      P(m,n,4) = P(m,n,4)+1; 
                      P(n,m,4) = P(m,n,4); 
                  end 
              end 
          end 
          if m==n 
              P(m,n,:) = P(m,n,:)*2; 
          end 
      end 
  end

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2018-2-6

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/380964-i-have-written-a-logic-for-co-occurance-matrix-but-it-is-taking-a-lot-of-time-is-there-any-other-to#answer_303623

You could vectorize. Or you could use graycomatrix()

6 个评论
显示 4更早的评论隐藏 4更早的评论

teja jayavarapu 2018-2-14

Sorry I didn't get you,can you explain more precisely.

Walter Roberson 2018-2-14

在 MATLAB Online 中打开

Under the conditions that all values in Gray are integers in the range 0 to 15, then your code

for m = 1:16

      for n = 1:16 
          for i = 1:M 
              for j = 1:N 
  j<N&Gray(i,j)==m-1&Gray(i,j+1)==n-1  %0 ° m for the row n for the column
                      P(m,n,1) = P(m,n,1)+1; 
                      P(n,m,1) = P(m,n,1); 
             end
           end
         end
       end

can be replaced by

V = @(M) M(:);
P0 = accumarray(1+[V(Gray(:,1:end-1)), V(Gray(:,2:end))], 1);

This will make P0 a 16 x 16 matrix containing the applicable counts.

Your other three conditions can be created with similar lines. You can then put all four of them together into your P matrix.

P = cat(3, P0, P45, P90, P135);

请先登录，再进行评论。

Answer 2

Roger Stafford 2018-2-14

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/380964-i-have-written-a-logic-for-co-occurance-matrix-but-it-is-taking-a-lot-of-time-is-there-any-other-to#answer_305024

编辑：Roger Stafford 2018-2-15

在 MATLAB Online 中打开

In the code you have written the tests are false the great majority of the cases, and that suggests strongly that the method can be made more efficient.

Since you mention “image” in connection with rows and columns of ‘Grey’, I will assume all the values in ‘Grey’ are non-negative integers. I will add 1 to the values of ‘Grey’ and replace any that then exceed 17 by 17 itself. This latter will make P have just one extra row and one extra column of false values which will be discarded at the end.

P = zeros(17,17,4);
G = reshape(min(Grey(:)+1,17),size(Grey));
for i = 1:M
 for j = 1:N-1
  m = G(i,j); 
  n = G(i,j+1);
  P(m,n,1) = P(m,n,1)+1;
 end
end
for i = 2:M
 for j = 1:N-1
  m = G(i,j); 
  n = G(i-1,j+1);
  P(m,n,2) = P(m,n,2)+1;
 end
end
for i = 1:M-1
 for j = 1:N
  m = G(i,j); 
  n = G(i+1,j);
  P(m,n,3) = P(m,n,3)+1;
 end
end
for i = 1:M-1
 for j = 1:N-1
  m = G(i,j); 
  n = G(i+1,j+1);
  P(m,n,4) = P(m,n,4)+1;
 end
end
P = P(1:16,1:16,:); % Trim off one row and one column
P = P + permute(P,[2,1,3]); % Replaces the "P(n,m,-)=P(m,n,-)" above

6 个评论
显示 4更早的评论隐藏 4更早的评论

Roger Stafford 2018-2-15

@Teja: Yes, that is an error. I have corrected it now. Thank you.

teja jayavarapu 2018-2-15

Can you give me idea about guassian internal normalisation

请先登录，再进行评论。

Answer 3

teja jayavarapu 2018-2-15

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/380964-i-have-written-a-logic-for-co-occurance-matrix-but-it-is-taking-a-lot-of-time-is-there-any-other-to#answer_305255

编辑：teja jayavarapu 2018-2-15

Ok,thank you for the support,can you please help me with the Gussian internal normalisation for texture parameters of (capacity,entropy,relevance,inverse difference)