Blurred Matlab figure window

Following my post two weeks ago about disabling an entire Matlab figure window, and my article last week about setting the transparency of a figure window, I would like to combine these two functionalities into a blurred-window effect for a disabled window.

The basic idea

The basic idea, as reader Mory pointed out in a comment, is to overlay a semi-transparent empty figure window, having just the right size and position, on top of the main (disabled) figure window:

Main (unblurred) window + Semi-transparent window = Blurred window effect

Main (unblurred) window + semi-transparent window = blurred window effect

In addition to ensuring the correct figure size and position, there are several other things we should care for: We need to synchronize the figure/blurring color, menubar/toolbar, and title. We also need to handle docking, resizing and figure movement. Finally we need to connect the two figures so that whenever one is closed then so is the other.


My blurFigure utility on the Matlab File Exchange attempts to handle all these setups for the user. The utility is quite simple to use:

blurFigure(hFig) blurs figure hFig and prevents interaction with it. The only interaction possible is with user-created controls on the blurring panel (see below).

hFigBlur = blurFigure(hFig) returns the overlaid blurred figure pane. This is useful to present a progress bar or other GUI controls, for user interaction during the blur phase (see the demo below).

blurFigure(hFig,STATE) sets the blur status of figure hFig to STATE, where state is ‘on’,’off’,true or false (default=’on’/true). blurFigure(hFig,’on’) or blurFigure(hFig,true) is the same as: blurFigure(hFig); blurFigure(hFig,’off’) or blurFigure(hFig,false) is the same as: close(hFigBlur).

blurFigure(‘demo’) displays a simple demo of the blurring. In fact, this runs the following simple code:

% Create the main (blurred) figure window
hFigMain = figure;
% Display some GUI controls in the main window
try oldWarn = warning('off','MATLAB:uitree:MigratingFunction'); catch, end
hTree = uitree('root','c:\');
try hTree.getTree.expandRow(0); catch, end
try warning(oldWarn); catch, end
uicontrol('string','click me!', 'units','pixel', 'pos',[300,50,100,20]);
axes('parent',gcf, 'units','pixel', 'pos',[230,100,300,300]);
set(gcf,'ToolBar','figure');  % restore the toolbar that was removed by the uicontrol() call above
% Call blurFigure() to add a semi-transparent overlaid window
hFigBlurTemp = blurFigure(hFigMain);
% Add some non-blurred controls on top of the blur
uicontrol('parent',hFigBlurTemp, 'style','text', 'units','pixel', 'pos',[130,85,390,80], ...
          'string','Processing - please wait...', 'FontSize',12, 'FontWeight','bold','Fore','red','Back','yellow');
jProgressBar = javacomponent('javax.swing.JProgressBar', [180,115,310,20], hFigBlurTemp);
uicontrol('parent',hFigBlurTemp, 'string','Cancel', 'pos',[280,90,100,20], 'Callback','close(gcbf)');

Non-blurred controls displayed over a blurred figure window

Non-blurred controls displayed over a blurred figure window

Do you have some other interesting uses for window transparency in Matlab? If so, please share your thought in a comment.

Categories: Figure window, GUI, Java, Listeners, Medium risk of breaking in future versions, Undocumented feature

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2 Responses to Blurred Matlab figure window

  1. Paul Andrews says:


    This is another great post. Thank you very much for sharing it. For those of us who are trying to develop professional applications using Matlab and the Matlab Compiler, your blog is extremely helpful.

    Now, I do have a suggestion regarding your blurFigure function. How about using a JWindow, with opacity set to 0.8, and overlaying it over the figure? JWindow has the advantage of not having boarders, titles, menubars, etc.
    The code below shows you what I had in mind.

    Best regards,


    %% Blur using JWindow
    % JWindow is like a JFrame, but without borders or menu bar. 
    jFrame = getjframe(h);
    % Create blank panel
    panel = javaObjectEDT('javax.swing.JPanel');
    % Create jWindow with jFrame as its owner, and add the blank panel
    jWindow = javax.swing.JWindow(jFrame); pause(0.1); % the pause is needed to ensure the object is created before proceeding
    % Pause
    disp('Press any key to blur the figure')
    %Set size and location to match jFrame
    % Make jWindow semi-transparent and visible

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