How to interrupt the roipoly function

Good morning,

I am having problems with the roipoly function. I would like to know if it is possible to interrupt/cancel the action of roipoly.

I mean, I have a button (in a GUI) that launches the roipoly function but if I press the button unintentionally the antion starts and I can not cancel the action.

Is there any way to cancel the action without having to select the points in the image?

Thank you very much,

Silvia

Answer 1

[Image Analyst]

If you put a title over your image that says to right click to cancel,

title('Left click vertices then right click to finish');
[x, y] = roipolyold();

then you can check if the returned point set is empty or less than 2, and if so, they bailed out.

if isempty(x) || length(x) <= 2
    % Not a complete polygon.  Better not continue with code or you'll get an error.
    return;
end

You can also use questdlg() to ask the user if the polygon is acceptable or not, and if not, have them redraw it.

[Silvia]

Thank you very much for the idea.

I have also found information about using a Robot to simulate that I have press the ESCAPE button.

I'll try both options.

Thank you again

Silvia