How to loop over images in a folder in an AppDesigner GUI?

Unfortunately, I have absolutely no experience with AppDesigner yet. If there is a good tutorial going in the direction of what I want to solve, I'd also appreciate a hint to the corresponding link.

Now to my problem: I have a folder filled with images that are named following the convention A_i.tif and B_i.tif, i.e. for every i there are two images A and B.

How can I create a GUI using AppDesigner that "loops" over all i = 1:N image pairs, displays one pair at a time and waits for the user to click one of 3 button options before the next image pair is loaded and displayed?

I am only asking for the "loop" functionality, I'll be able to do the rest. The rather generic code frame is

    classdef ManualCheckGUI < matlab.apps.AppBase

    % Properties that correspond to app components
    properties (Access = public)
        UIFigure      matlab.ui.Figure
        UIAxes        matlab.ui.control.UIAxes
        UIAxes2       matlab.ui.control.UIAxes
        KeepButton    matlab.ui.control.Button
        RemoveButton  matlab.ui.control.Button
        UndoButton    matlab.ui.control.Button
    end

    methods (Access = private)

        % Button pushed function: KeepButton
        function KeepButtonPushed(app, event)

        end

        % Button pushed function: RemoveButton
        function RemoveButtonPushed(app, event)

        end

        % Button pushed function: UndoButton
        function UndoButtonPushed(app, event)

        end
    end

    % App initialization and construction
    methods (Access = private)

        % Create UIFigure and components
        function createComponents(app)

            % Create UIFigure
            app.UIFigure = uifigure;
            app.UIFigure.Position = [100 100 640 480];
            app.UIFigure.Name = 'UI Figure';
            setAutoResize(app, app.UIFigure, true)

            % Create UIAxes
            app.UIAxes = uiaxes(app.UIFigure);
            title(app.UIAxes, 'Title');
            xlabel(app.UIAxes, 'X');
            ylabel(app.UIAxes, 'Y');
            app.UIAxes.Position = [16 160 300 185];

            % Create UIAxes2
            app.UIAxes2 = uiaxes(app.UIFigure);
            title(app.UIAxes2, 'Title');
            xlabel(app.UIAxes2, 'X');
            ylabel(app.UIAxes2, 'Y');
            app.UIAxes2.Position = [325 160 300 185];

            % Create KeepButton
            app.KeepButton = uibutton(app.UIFigure, 'push');
            app.KeepButton.ButtonPushedFcn = createCallbackFcn(app, @KeepButtonPushed, true);
            app.KeepButton.Position = [134 110 100 22];
            app.KeepButton.Text = 'Keep';

            % Create RemoveButton
            app.RemoveButton = uibutton(app.UIFigure, 'push');
            app.RemoveButton.ButtonPushedFcn = createCallbackFcn(app, @RemoveButtonPushed, true);
            app.RemoveButton.Position = [449 110 100 22];
            app.RemoveButton.Text = 'Remove';

            % Create UndoButton
            app.UndoButton = uibutton(app.UIFigure, 'push');
            app.UndoButton.ButtonPushedFcn = createCallbackFcn(app, @UndoButtonPushed, true);
            app.UndoButton.Position = [289 110 100 22];
            app.UndoButton.Text = 'Undo';
        end
    end

    methods (Access = public)

        % Construct app
        function app = ManualCheckGUI()

            % Create and configure components
            createComponents(app)

            % Register the app with App Designer
            registerApp(app, app.UIFigure)

            if nargout == 0
                clear app
            end
        end

        % Code that executes before app deletion
        function delete(app)

            % Delete UIFigure when app is deleted
            delete(app.UIFigure)
        end
    end
end

Answer 1

[Praveen Reddy]

Hi Michael,

I understand that you want to loop through all images in a folder but wait for the user to perform a UI activity before loading the next pair of images. You can use a state variable in the for loop to pause the execution (Alternatively state button). Toggle the state value in appropriate call back functions to resume the for loop. I have tried to replicate the functionality with a text box; however, you can use the similar logic with an image panel component instead of text box. I have attached the mlapp file for reference.

The following resources also might help you:

• https://www.mathworks.com/matlabcentral/answers/418893-how-to-display-an-image-in-ui-figure-on-app-designer
• https://www.mathworks.com/matlabcentral/answers/401480-how-do-i-run-all-images-in-a-folder-through-an-image-processing-code
• https://www.mathworks.com/matlabcentral/answers/399998-add-static-images-with-app-designer#answer_367315