How to clear images in app designer

Hello guys,

I am trying to clear the image when I click the reset button. I tried the following two commands.

clf(app.Image3)

cla(app.Image3, 'reset')

Do you recommend other commands to use?

Answer 1

[Image Analyst]

clf clears a whole figure, not just one axes on the figure. It clears everything I believe. So, since that is never anything I want to do I never use it.

cla clears just the current axes or the one you told it to. I use this one a lot because I want to make sure the axes gets cleared. Often I put "hold on" to draw graphics in the overlay and forget to turn it off. If you don't call cla then display a new image, it will just add to the axes and be on top covering everything that was there before. If you do that enough, like dozens or hundreds of times, your memory will get exhausted and your program will get slower and slower.

[Othman Alkandri]

Thank you for your answer. I want to clarify something please. I am using the image control, not the axes control as shown in the screenshot below:

[Image Analyst]

If you attach the .mlapp file, maybe I can see what's going on.

[Image Analyst]

Here is one way. You can set the ImageSource to a small white image of whatever color you want.

% Button pushed function: DisplayImageButton
function DisplayImageButtonPushed(app, event)
% Get selected filename from listbox.
selectedFileName = app.ListBox.Value;
if isempty(selectedFileName)
    return;
end
% Display image in the axes control.
theImage = imread(selectedFileName);
imshow(theImage, 'Parent', app.UIAxes);
% Display image in the "Image" control.
app.Image.ImageSource = theImage;
end

% Button pushed function: ClearImagesButton
function ClearImagesButtonPushed(app, event)
cla(app.UIAxes, 'reset'); % Clear axes control.
app.Image.ImageSource = 255*ones(2,2,3); % Clear image control.
end

See attached demo.

[Othman Alkandri]

thank you, I like the idea of setting the ImageSource to a small white images