Real-time editable ROI with mask

Hello everyone, I'm working with data processing and I have a problem.

I have a 2-D matrix data, and I want to draw a ROI on it and see the data inside the ROI. I used 'drawpolygon' and 'createMask' to do this. To make things easier to be understood, I just put a similar code I'm using here:

a = magic(8);

imagesc(a);

b = drawpolygon;

c = createMask(b);

cc = c.*a;

d = sum(cc,[1,2]);

The problem is, I want to drag or edit the ROI and have the calculated data ('d' here) to be changed together at the same time. Which means that when I finish drawing the ROI, I will have the calculated data; and once I make change to the ROI, the calculated data changes as well. And at last I have to delete the ROI and save the mask and the calculated data. I've looked up 'addlistener' but not sure how it works.

Any help or suggestions are welcomed, thanks.

Answer 1

[Shubham Rawat]

Hi Yang,

I have reproduced your code and got the results in Real time. You may use this code to do the things:

a = magic(8);
imagesc(a);
b = drawpolygon;

%draw polygon in the figure;

l = addlistener(b,'MovingROI',@(src,evt)clickCallback(src,evt,b,a)); %this listener I have added to listen whenever we move ROI

the function for the callback is here:

function clickCallback(src,evt,b,a)

c = createMask(b);
cc = c.*a;
d = sum(cc,[1,2]);
disp(d); %displaying the values of d

end

You may use these links to know more about Callbacks and the example which I have used for this.

Hope this Helps!

[Yang LIU]

Thank you for your answer, I think it works well for my problem!