function []=im_pos(cmd,cmddata)
%IM_POS Write image position and pixel value
% IM_POS() writes the value of the image corresponding to the
% current pointer position. The value is written in the window.
%
% To use it, set the 'ButtonDownFcn' property of the image
% to 'im_pos', e.g.,
% set(findobj(gcf,'type','image'),'ButtonDownFcn','im_pos');
%
% You can get the value of the array rather than the colormap
% index by setting the 'UserData' property of the image to
% the matrix and setting the 'UserData' property of the figure
% to the magic number 1.17100, e.g., if the image displays
% matrix X
% set(findobj(gcf,'type','image'),'UserData',X);
% set(gcf,'UserData',1.17100);
% This isn't necessary for Matlab Version 5.
%
% You can get the colormap index value zero relative (rather than
% Matlab's 1 relative, useful for 8 bit images) by setting the
% 'UserData' property of the figure to the magic number 1.19108,
% e.g.,
% set(gcf,'UserData',1.19108);
% This will also use the 'UserData' of the image if it is
% not empty. This isn't necessary for Matlab Version 5.
%
% [No Guarantees. M. Lubinski]
% 09/15/93 Written by Mark Lubinski (lubinski@eecs.umich.edu)
% 08/23/95 M.L. Updated to display in window
% 03/14/96 M.L. Updated to check if should subtract 1 in value shown
% 03/10/97 M.L. Added limits to use axes limits
% 03/18/97 M.L. Set neg. numbers to use same number of characters
% 07/23/97 M.L. Updated comments and added useuserdata
% Allow defaults
if nargin<2, cmddata=gcf; end
if nargin<1, cmd='d'; end
% Need to change these if function name changes
str_u='im_pos(''u'',gcf);'; % Callback for window button up
str_m='im_pos(''m'',gcf);'; % Callback for window button motion
magicnum0=1.19108; % =ascii for 'wl'
magicnumU=1.17100; % =ascii for 'ud'
% Strategy:
% When mouse button is pressed DOWN
% 1) Create a text uicontrol to display values into (with
% tag='TMP_TXT').
% 2) Save the current window button up and motion callbacks and the
% pointer into TMP_TXT's user data for resetting later
% 3) Set the current window button up and motion callbacks to call
% this function with appropraite arguments
% 4) Create global array called POINT_IMAGEN where N=figure
% with image data matrix
% 5) Call this function as if the mouse button moved
% When mouse button is MOVED
% 1) Get the current position
% 2) If the position corresponds to a point in the image,
% then display the position and image value at that position
% (using the global matrix POINT_IMAGEN)
% When the mouse button is UP (or the pointer is ouside of the image)
% 1) Reset the current window button up and motion callbacks and the
% pointer from the values saved in TMP_TXT's user data
% 2) Return
% Globalize image data matrix to get values from
fh=gcf;
pi = ['POINT_IMAGE',int2str(fh)];
eval(['global ',pi]);
% Check if button up or not current figure
if (cmddata(1) ~= fh) | (strcmp(cmd,'u'))
% Button UP or no longer current figure
% So cleanup, reset and exit
h=findobj(cmddata(1),'Tag','TMP_TXT');
if isempty(h)
TMP_WBU=get(cmddata(1),'WindowButtonU');
TMP_WBM=get(cmddata(1),'WindowButtonM');
TMP_P='arrow';
else
TMP=get(h,'Userdata');
TMP_WBU=deblank(TMP(1,:));
TMP_WBM=deblank(TMP(2,:));
TMP_P=deblank(TMP(3,:));
set(h,'visible','off');
end
if strcmp(TMP_WBU,str_u)
set(cmddata(1),'WindowButtonUp','');
else
set(cmddata(1),'WindowButtonUp',TMP_WBU);
end
if strcmp(TMP_WBM,str_m)
set(cmddata(1),'WindowButtonMot','');
else
set(cmddata(1),'WindowButtonMot',TMP_WBM);
end
set(cmddata(1),'pointer',TMP_P);
% Check if global image values should be retained for speed
relative0=get(fh,'UserData');
if isempty(relative0)
relative0 = 0;
else
relative0 = (relative0(1) == magicnum0);
end
if ~relative0
eval([pi '=[];']); % Clear global data
end
return
end
% Check which action
if strcmp(cmd,'m')
% Button MOTION
h=findobj(fh,'Tag','TMP_TXT');
if isempty(h)
im_pos('u',fh);
return
end
ca=get(fh,'CurrentAxes');
pos=get(ca,'CurrentPoint');
pos=round(pos(1,1:2));
xlim=ceil(get(ca,'Xlim'));
ylim=ceil(get(ca,'Ylim'));
if ((pos(1)>=xlim(1)) & (pos(1)<xlim(2)) & ...
(pos(2)>=ylim(1)) & (pos(2)<ylim(2)))
% DEBUG disp(sprintf('%s(%d,%d)',pi,pos(2)-ylim(1)+1,pos(1)-xlim(1)+1));
val=eval([pi,'(pos(2)-ylim(1)+1,pos(1)-xlim(1)+1)']);
if fix(val)==val
fmt='%d';
elseif (abs(val)<10) & (abs(val)>0.01)
if val>0
fmt='%.4f';
else
fmt='%.3f';
end
elseif val>0
fmt='%.4e';
else
fmt='%.3e';
end
s_val=sprintf(fmt,val);
set(h,'String',sprintf('(%d,%d)=%s',pos(2),pos(1),s_val));
else
im_pos('u',fh);
return
end
elseif strcmp(cmd,'d')
% Button DOWN
if isempty(gco), return; end
if ~strcmp(get(gco,'Type'),'image'), return; end
TMP_WBU=get(fh,'WindowButtonUp');
TMP_WBM=get(fh,'WindowButtonMot');
TMP_P=get(fh,'pointer');
h=findobj(fh,'Tag','TMP_TXT');
if isempty(h)
uicontrol('Units','pix','pos',[0 0 150 20],'Style','text',...
'String','(x,y)=val','Horiz','left','Backg',[0 0 0],...
'Foreg',[1 1 1],'Tag','TMP_TXT','Userdata',...
str2mat(TMP_WBU,TMP_WBM,TMP_P));
else
set(h,'Visible','on');
end
set(fh,'WindowButtonMot',str_m,'WindowButtonUp',str_u);
% Check if image value should be userdata or colormap index (zero relative)
relative0=get(fh,'UserData');
useuserdata=0;
if isempty(relative0)
relative0=0;
else
useuserdata = (relative0(1)==magicnumU);
relative0 = (relative0(1)==magicnum0);
end
if (isempty(eval(pi))) & (relative0 | useuserdata)
eval([pi,'=get(gco,''UserData'');']);
end
if (isempty(eval(pi)))
if relative0
eval([pi,'=get(gco,''CData'')-1;']);
else
eval([pi,'=get(gco,''CData'');']);
end
end
set(fh,'Pointer','crosshair');
im_pos('m',fh);
end
% END function IM_POS
