Number of pixels while modifying freehand on a figure

Hi there,

Is there a way so matlab contniously display the number of the pixels within ROI as Im modyfing the shape (shape of freehand) object on a figure?

So for example I displayed a freehand object on my matlab figure, now I want to modify the shape using the WayPoints, tho while Im modifying I need to khow much my number of pixels within the ROI changes.

I would really appreciate it, if you can help me with this issue.

Thank you.

Nikan

Answer 1

[DGM]

Here is a very simple example

inpict = imread('cameraman.tif');

% show image and make ROI
imshow(inpict);
R = drawfreehand(gca);

% specify CBF to be executed when ROI is moved
addlistener(R,'MovingROI',@whenmove);
addlistener(R,'ROIMoved',@whenmove);

% show initial area before manipulation
area = sum(sum(createMask(R)))

% function to be executed whenever ROI or nodes are moved
function whenmove(R,~)
	% just dump the area to console
    % you can choose to do something fancier
	area = sum(sum(createMask(R)))
end

As an example of "something fancier", you might want to tidy up console output a bit. This is a very crude approach, but it's cleaner than dumping everything.

% pad the console so that redraw doesn't back into prior output/warnings
fprintf('\n                  \n')

% function to be executed whenever ROI or nodes are moved
function whenmove(R,~)
	area = sum(sum(createMask(R)));
	rpad = sprintf(repmat(sprintf('\b'),[1 19]));
	thisnum = sprintf('%d',area);
	fprintf([rpad 'Area is ' thisnum repmat(' ',[1 10-numel(thisnum)]) '\n'])
end