How to select a regionprops from a popup menu in a GUI?

Dear all,

I am building one GUI which include a popup menu for a 'regionprops' function that I need. I am trying to call the type of 'regionprops' after clicking a push button but it is not working. My code is as follows:

popup_2_Value = get(handles.popupmenu2, 'Value');
if popup_2_Value == 1
    RegPropType = 'Area';
elseif popup_2_Value == 2
  RegPropType = 'MajorAxisLength';
elseif popup_2_Value == 3
  RegPropType = 'MinorAxisLength';
elseif popup_2_Value == 4
  RegPropType = 'Perimeter';
elseif popup_2_Value == 5
  RegPropType = 'Orientation';
end

% 

X = im2bw(I); %binary image of the input

CC = bwconncomp(X); %Connected components
mal = regionprops(CC,'RegPropType'); % normal code format is --> mal = regionprops(CC,'Area');
mal = vertcat(mal(:).RegPropType);   % normal code format is --> mal = vertcat(mal(:).Area);

This error message appears "Error using regionprops>getPropsFromInput"

Any idea how to solve such problem?

With kind regard,

Meshoo

Answer 1

[ES]

From what I see, you should have done

mal = regionprops(CC,RegPropType)

instead of

mal = regionprops(CC,'RegPropType');%Note the missing quotes

Since the variable RegPropType has the required string like 'area' or ' Perimeter' etc. When you pass as 'RegPropType', this string itself is passed, and not the value inside the variable RegPropType.

[Meshooo]

Yes, you are right for the first part. As you said it should be

mal = regionprops(CC,RegPropType)

But how can we do the following second part

mal = vertcat(mal(:).RegPropType);

Thank you very much.

[ES]

you can do an eval.

mal = eval(['vertcat(mal(:).',RegPropType]);