Issue using imcrop in a script

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Alex Mason
Alex Mason on 27 Jul 2021
Commented: Jonas on 28 Jul 2021
Hello
I am using imcrop to perform a "live" crop. So
[init_crop,crop]=imcrop(init_img)
So this pops open a figure with the image "init_img" and allows me to draw a box around the bit I want to crop.
init_crop, crop returns the cropped image and the bounding box.
This works fine in isolation. It also works if I am stepping through. If I run the script proper, the live cropping function appears to not work at all. I get shown the image, but I am not able to draw a box around the area I want. The program then just waits around for me to select my crop, but I can't!
Fuller code:
camList = webcamlist
cam = webcam(2)
init_img = snapshot(cam);
init_img = rgb2gray(init_img);
figure
imshow(init_img)
[init_crop,crop]=imcrop(init_img);
disp(crop)
imshow(init_crop)
  3 Comments
Alex Mason
Alex Mason on 27 Jul 2021
Yes of course. However, this initial bit of code is for setting up the crop. So the user takes a sample image from the webcam and draws the crop box.
This box is then used later to do other things. e.g. I have a loop that periodically takes images from the webcam and the crop box is re-used here to select the area of interest automatically.
But at the start, I do need the user to define where the crop should be.
Jonas
Jonas on 28 Jul 2021
you can try using ginput and round the output data to pixels. unfortunately i can not test your code because i do not have a webcam at the moment

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