发信人: Genial (山城棒棒儿军), 信区: MathTools
标  题: 动态显示鼠标的坐标值和图像像素值 zz
发信站: 饮水思源 (2003年12月19日00:19:10 星期五), 站内信件

对于动态显示鼠标的坐标值和像素值，在其他语言如vc,vb中都比较方便，有直接的着方
面的函数，那么在matlab图像处理里面又如何实现呢？
具体的实现方法很多，但归结起来就是获取坐标轴的current point 属性值，我这里给
出的一个函数是从mathworks 获取柄稍作修改后的结果，相信对做图像处理的朋友有一
定的作用。另一个就是自带的pixval函数。谁有不同的实现方法，请多多共享啊！

function dynpoint(arg,h)
% Show the coordinates of a plot dynamically
%
% To start use:
% dynpoint(h)
% where h is a handle to a figure, axes or e.g. line.
%
% To delete use:
% dynpoint('delete',h)
% where h is a handle to a figure, axes or e.g. line.
% (you may also use: dynpoint delete)
%
% There can only be one dynamic plotter in a figure at a time.
%
% Example:
% subplot(211), hline = plot(sin(1:10))
% subplot(212), plot(sin(1:100))
% dynpoint(hline)

% 2002,6.29

if ~exist('arg','var')
   arg = gcf;
end

if ~isstr(arg)
 handle = arg;
 arg = 'init';
end

switch arg
case 'init'
   if ~ishandle(handle)
       error('h is not a handle')
   end

   [h,ax] = h2hax(handle);

   % delete old dynamic text object
   ht = findobj(h,'tag',[mfilename '_text']);
   if any(ht)
       delete(ht)
   end

   % text window at the bottom left corner
   % text in centred
   uicontrol(h,...
       'style','text',...
       'pos',[2 2 200 15],...
       'tag',[mfilename '_text'],...
       'userdata',ax(1))

   % do the dynamic thing...
   set(h,'windowbuttonmotionfcn',[mfilename ' move'])

case 'move'
   ht = findobj(gcbf,'tag',[mfilename '_text']);
   ax = overobj('axes');
   if ~any(ax)
       ax = get(ht,'userdata');
   end
   p = get(ax,'currentpoint');
   set(ht,'string',sprintf('(%g, %g)', p(1), p(3)));

case 'delete'
   if ~exist('h','var')
       h = gcf;
   end
    [h,ax] = h2hax(h);
   set(h,'windowbuttonmotionfcn','')

   ht = findobj(h,'tag',[mfilename '_text']);
   delete(ht)

end

% ----------
function [h,ax]=h2hax(handle)

typ = get(handle,'type');
if strcmp(typ,'figure')
   h = handle;
   ax = findobj(h,'type','axes');
elseif strcmp(typ, 'axes')
   h = get(handle,'parent');
   ax = handle;
elseif strcmp( get(get(handle,'parent'), 'type'), 'axes' )
   ax = get(handle,'parent');
   h = get(ax,'parent');
end