Modifying impixelinfo to display 3d coordinates

I want to display real world image coordinates (imrealinfo function)when user move the mouse over the image.

I have to get the image pixel coordinates with impixelinfoval Then I know the real world coordinate of the left top position of the image (origin in image space) also the pixel width

My code is

X3d = realcor(1,1) + realcor(3,1)* X;  

Y3d = realcor(2,1) + realcor(4,1)* Y;  

Z3d = Zdata(X3d, Y3d);

% realcor contain real world coordinates of left top corner of the image, pixel width
% Zdata contain Z details

X, Y are the output of impixelinfoval function.

so my new function should get the output of impixelinfoval and then compute the 3d coordinates and when user move the mouse imrealinfo command should show the 3d real coordinates of that point.

Any suggestion please

[bes]

My problems are 1. how assign impixelinfoval output to x and y to compute 3d coordinate 2. How to display 3d coordinate when cursor moves?

Is there any way to get the impixelinfoval outputs to [x y] array?

Answer 1

[Matt Kindig]

I don't believe that impixelinfo or impixelinfoval allows you to specify a custom callback, which is what you would need to do what you are intending.

However, it should be relatively straightforward to essentially implement your own imrealinfo() function that does what you want to do. Are you familiar with writing your own custom callback functions? One way to structure your code is something like this (this is just the skeleton of the code-- this hasn't been tested and should probably be expanded to include error checking, etc.).

function imrealinfo( himg, ZData, realcor)
  % hfig is handle to your image
  % ZData and realcor are your "real-world" info

   hax = get(himg, 'parent');  %handle to axes
   hfig = get(hax, 'parent');  %handle to figure
   hu = uicontrol('Style','edit', 'String', 'X3d=0, Y3d=0, Z3d=0')
   set(hfig, 'WindowButtonMotionFcn', @motioncb)    

   function motioncb(src,evnt)
      cp = get(hax, 'CurrentPoint');
      X = cp(1,1);
      Y = cp(1,2);
      X3d = realcor(1,1) + realcor(3,1)* X;
      Y3d = realcor(2,1) + realcor(4,1)* Y;
      Z3d = Zdata(X3d, Y3d);
      set(hu, 'String', sprintf('X3d=%0.2f,  Y3d=%0.2f, Z3d=%0.2f', X3d, Y3d, Z3d)); 
   end

end

[bes]

Thanks.

Answer 2

[Walter Roberson]

Perhaps you could do this with datacursormode . It allows custom callbacks for information display.

[bes]

thanks