App designer - problem with thresholding image

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Hi folks,
I have the app attached, in which I am encountering two issues. Firstly, when trying to threshold an image and displaying the thresholded image, it would appear my function calls aren't working as the image displayed is not thresholded. (ResinThreshold function works in live editor, but not when called in app designer). The thresholding function is below.
Thanks
function ResinThreshold(app)
imgGrey = rgb2gray(app.img);
[counts, ~] = imhist(imgGrey, 255);
T = otsuthresh(counts);
BW = imbinarize(imgGrey, T);
BW = bwareaopen(BW, 3000);
BW = imfill(BW, 'holes');
BW = bwperim(BW);
BW = imdilate(BW, ones(5));
BW = imerode(BW, ones(3));
BW = imfill(BW, 'holes');
app.img = app.img.*repmat(uint8(BW),[1 1 3]);
end
  2 Comments
Teshan Rezel
Teshan Rezel on 11 Apr 2021
hi @DGM, apologies! I thought I'd attached it...I've ammended the error!

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Accepted Answer

Image Analyst
Image Analyst on 11 Apr 2021
You need to display the output image
imshow(app.img);
  5 Comments
Image Analyst
Image Analyst on 11 Apr 2021
Edited: Image Analyst on 11 Apr 2021
I ran it but didn't know what to do. There are no instructions. You should do what I do. Have a listbox listing all the images, then a series of controls (checkboxes, pushbuttons, etc.) that say "Step 1 : select an image", "Step 2 : Select any options", "Step 3 : Mark Points", "Step 4 : Analyze selected ponts" or whatever. That will essentially guide the user through the various steps without a user manual or training. Otherwise, attach the software manual for it (though I'm not sure I'll read it if it's too lengthy).
Teshan Rezel
Teshan Rezel on 11 Apr 2021
hi @Image Analyst, so the app should prompt you to select a folder with images in it on startup. once selected, pushing any of the buttons on the left of the table will move increment the relevant tally and display the next image in sequence.
I haven't listed any instructions as this is a very specific app designed for use by a very few people, and its based entirely on an existing "manual" methodology. Typically, they will go through hundreds of images on the app and tally them up, so it's not feasible to implement a listbox for images.

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R2020b

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