MATLAB: How to convert ‘Structure’ ?!

Question

Hi everybody;

I am trying to get feature value out of structure array..

for example:

glcms = graycomatrix(CG,'Offset',[0 1]);

Cont_RGB = graycoprops(glcms,'Contrast');

F=Cont_RGB;

F= Contrast: 0.2546 % i wana to remove word contrast and get the number only!

How can i get the number?

Thank you

Answer 1

If your

Cont_RGB = graycoprops(glcms,'Contrast');

is returning a Cont_RGB which is a structure array, and you want to extract the field named "Contrast" from the first member of that structure array, you would use

Cont_RGB(1).Contrast

and in the cast where the structure array only has a single member (so Cont_RGB(2) does not exist) then you can abbreviate that to

Cont_RGB.Contrast

In the above, the period is part of the syntax.

If Cont_RGB is a structure array, so Cont_RGB(2).Contrast and so on exist, and you are trying to get a vector equivalent to

[Cont_RGB(1).Contrast Cont_RGB(2).Contrast Cont_RGB(3).Contrast ....]

then use

[Cont_RGB.Contrast]

In this, the [] and the period are part of the syntax.