Haralik features : Maximal Correlation Coefficient

Hi Guys, I am working on haralik features and so far I managed to find all the 13 features except for Maximal Correlation Coefficient, that should be calculated as:

I've already define the px and py:

p_x(i,k) = p_x(i,k) + glcm(i,j,k); 
p_y(i,k) = p_y(i,k) + glcm(j,i,k);
p(i,j)=glcm(i,j,k)

I ahve 4 offsets

thank u in advance for ur comments

[Image Analyst]

What are Q, p, px, and py? Which is your image? How did you get the glcm array? How does your equation compute Q(i, j)?

[Hend Abouche]

glcm is the results of graycomatrix(gry,'offset',offsets); using a gray image, p is co-occurence probability matrix,

px(i): i-th entry in the marginal-probability matrix obtained by summing the rows of p(i,j)

py(j): j-th entry in the marginal-probability matrix obtained by summing the columns of p(i,j)

I used this website equations https://earlglynn.github.io/RNotes/package/EBImage/Haralick-Textural-Features.html

PS: I normalized the data: glcm = glcm./sum(glcm(:));

Answer 1

[Image Analyst]

You need to have 3 nested loops. The outer one would be over j (columns). The middle one would be over i (rows). The innermost one would be over k.

[rows, columns] = size(p)
for j = 1 : columns
    for i = 1 : rows
        numerator = 0;
        denominator = 0;
        for k = 1 : columns
            numerator = numerator + p(i, k) * p(j, k);
            denominator = denominator + px(i) * py(k);
        end
        Q(i, j) = sum(numerator / denominator);
    end
end

[Hend Abouche]

Thank you for your answer, this really makes sense but why you assumed that K is about columns not rows (cuz that the issue that I had which is to know wich value I should give to K )

[Image Analyst]

k is columns because it's in the second dimension of p(i,k) and p(j,k). Matrices like that are indexed as p(row, column) so therefore k represents column.

[Hend Abouche]

alright thank you so much

[Serhat Yesilkoy]

hi,I didn't understand the part of how the marginal probability functions px and py are defined.Unrecognized function or variable 'px'.Unrecognized function or variable 'px'. I am facing the problem.