imrotate in Matlab App Desinger

Hello,

Is it possible to rotate an image in Matlab app designer?

I input an image using the following code:

% Code that executes after component creation
        function startupFcn(app)
            imag = imread('cameraman.tif');
            handles.I = imresize(imag,0.75);
            imshow(handles.I,'Parent',app.UIAxes)
        end

How to now rotate the image using a slider.

Under the slider code, I have tried the following but could not get it to work:

% Value changing function: SteeringSlider
        function SteeringSliderValueChanging(app, event)
            changingValue = event.Value;

              angle = round(event.Value);
              imshow( imrotate(app.UIAxes,angle,'bilinear','crop') );
          end

Can you tell me how to rotate an image in Matlab App Designer? Thanks.

Answer 1

[Rajesh Balagam]

Refer to the answer in the following page:

https://www.mathworks.com/matlabcentral/answers/360834-rotate-image-in-matlab-app-designer

Answer 2

[Sean de Wolski]

You're calling imshow on the uiaxes not the image. I would manage this like this:

app.UIAxes = uiaxes; % You won't need this in app designer since it's already there
im = imread('cameraman.tif');
imh = imshow(im, 'Parent', app.UIAxes);
for angle = 0:10:360
  imh.CData = imrotate(im,angle,'bilinear','crop');
  pause(0.25)
end

Store imh and im as properties of your app.

[monkey_matlab]

I tried your suggestion but still did not get the image to rotate.

Here is my code from App Designer:

properties (Access = public)
      imageData = imread('cameraman.tif'); % Description
      im
      imh
  end

    methods (Access = private)

        % Code that executes after component creation
        function startupFcn(app)
            %imshow(app.imageData,'Parent',app.UIAxes);
            %im = imread('cameraman.tif');
            imh = imshow(app.imageData, 'Parent', app.UIAxes);

        end

        % Callback function
        function SteeringSliderValueChanged(app, event)

        end

        % Value changed function: Steer_ValueEditField
        function Steer_ValueEditFieldValueChanged(app, event)
            %value = app.Steer_ValueEditField.Value;
            changingValue = app.SteeringSlider.Value;

        end

        % Value changing function: SteeringSlider
        function SteeringSliderValueChanging(app, event)
            changingValue = event.Value;
            angle = round(changingValue);
            app.imh.CData = imrotate(app.imageData, angle, 'bilinear', 'crop');
            drawnow limitrate

            % Set numeric display to latest slider value
            app.Steer_ValueEditField.Value = changingValue; 
        end

[Sean de Wolski]

app.imh.CData = imrotate(app.imageData, ...)
drawnow limitrate

You're rotating the handle not the image data and also need to reference app. Also

[monkey_matlab]

I edited the code as per your suggestion (see updated code above) but the image is still not rotating when I move the slider.