gray image app design

I am trying to convert and display the gray image from the left green image into the right one. However, the gray image will pop up separately instead of inside the app. Hope someone can help soon. Thank you!

[Rik]

You should teach yourself the habit of specifying the parent every time you create a graphics object. In this case you create an axes without specifying the parent, so that will probably create a new axes object in a normal figure, instead of creating one in your uifigure.

Answer 1

[Image Analyst]

Try getting rid of the ax=axes line. That probably makes a new axes, which you don't need or want since you created them all already in App Designer.

[Shu-An Hsieh]

I got this error after I removed it.

[Image Analyst]

rgb2gray takes an image, not a filename. Try

rgbImage = imread(fileName);
% Get the dimensions of the image.
% numberOfColorChannels should be = 1 for a gray scale image, and 3 for an RGB color image.
[rows, columns, numberOfColorChannels] = size(rgbImage)
if numberOfColorChannels > 1
	% Convert from RGB to gray scale.
	grayImage = rgb2gray(rgbImage);
else
    % It's already a gray scale image.
    grayImage = rgbImage;
end
imshow(rgbImage, 'Parent', app.UIAxes3);
imshow(grayImage, 'Parent', app.UIAxes2);