image pixel info on

Hello.

I have 2 different images (image1, image2). I want to place the mouse (or click with it) on image1 (to get the (x,y) of that pixel), and to view the pixel value of image2 on that (x,y) location (the one I choose on image1).

how can that be done?

thanks.

Answer 1

[Martin]

Hi Nirit, you can use the WindwoButtonMotionFunction of the Figure, your image 1 is in. Here is a quick example:

function m_easy_mouse_handling_example()

%example data
a = [1,1,1;2,2,2;3,3,3];
b = [10,12,14;16,18,20; 22 24 26];

%show the two figures
h_fig1 = figure()
h_ax1 = axes('Parent',h_fig1);
h_im1 = imagesc(a,'Parent',h_ax1);

h_fig2 = figure()
h_ax2 = axes('Parent',h_fig2);
h_im2 = imagesc(b,'Parent',h_ax2);

%set function which is used when mouse is over figure 1 (h_fig1)
set(h_fig1,'WindowButtonMotionFcn', @MouseMoveFcn)

function MouseMoveFcn(varargin)
    try
     mouse_pos = get(h_ax1, 'CurrentPoint');
     ii = round(mouse_pos(1,1));
     jj = round(mouse_pos(1,2));

       %show value of image 2 in command line
       disp(num2str(b(jj,ii)))  %please check, if order of dimensions is correct
      catch
          %catch error, if you are outside the image (to do)
      end
  end

[nirit]

This seems to answer it. but now I have another problem:

both of the images are in unit16 (960x600). when I try to send them to MouseMoveFcn.m , for some reason, MouseMoveFcn.m receives them as:

   WindowMouseData with properties:

       Source: [1x1 Figure]
    EventName: 'WindowMouseMotion'

what am i doing wrong? I only change the set to this:

set(h_fig1,'WindowButtonMotionFcn', {@MouseMoveFcn,h_ax1,a,b});

and :

function MouseMoveFcn (varargin)
    display(varargin{2});
end