How to draw free-hand sketches using imfreehand ?

I have to take as input hand drawn sketches ... I have tried using imfreehand() but it completes the figures itself.

I also tried the solution provided by Doug Schwarz in http://www.mathworks.in/matlabcentral/newsreader/view_thread/30168#75552 where he coded the following :

    function sketch(cmd)
  if nargin == 0
      cmd = 'init';
  end

switch cmd
case 'init'
    fig = figure('DoubleBuffer','on','back','off');
    info.ax = axes('XLim',[0 1],'YLim',[0 1]);
    info.drawing = [];
    info.x = [];
    info.y = [];
    set(fig,'UserData',info,...
            'WindowButtonDownFcn',[mfilename,' down'])

case 'down'
    myname = mfilename;
    fig = gcbf;
    info = get(fig,'UserData');
    curpos = get(info.ax,'CurrentPoint');
    info.x = curpos(1,1);
    info.y = curpos(1,2);
    info.drawing = line(info.x,info.y,'Color','k');
    set(fig,'UserData',info,...
            'WindowButtonMotionFcn',[myname,' move'],...
            'WindowButtonUpFcn',[myname,' up'])

case 'move'
    fig = gcbf;
    info = get(fig,'UserData');
    curpos = get(info.ax,'CurrentPoint');
    info.x = [info.x;curpos(1,1)];
    info.y = [info.y;curpos(1,2)];
    set(info.drawing,'XData',info.x,'YData',info.y)
    set(fig,'UserData',info)

case 'up'
    fig = gcbf;
    set(fig,'WindowButtonMotionFcn','',...
            'WindowButtonUpFcn','')

end    

But I am not able to save the sketch being drawn or access it ..

Please help ...

Answer 1

[Walter Roberson]

After the sketch use

info = get(gcf, 'Userdata')

The result will be a structure with .x and .y coordinate lists.

[Avi Pal]

Sir, can you please elaborate a little; how can use info ? or if can save the image it will also do .

Answer 2

[Image Analyst]

If you want to use imfreehand to get x,y coordinates, you can do that. Here's s snippet from my demo:

hFH = imfreehand();
% Create a binary image ("mask") from the ROI object.
binaryImage = hFH.createMask();

% Just for demo purposes, get the x,y coordinates.  
% We don't use them though in this demo.
xy = hFH.getPosition;

[Avi Pal]

After drawing the sketch, i have to convex hull on it, so how can access the image in it ?

[Image Analyst]

You can use convhull on the (x,y) coordinates.