Questions

1. Show with a binary image that morphological opening and closing are dual operations. (Hint: apply opening on an image foreground and closing on the image background with the same structuring element)
2. Automatically crop an image using the convex hull of the object in it (the problem is taken from https://stackoverflow.com/questions/14211340/automatically-cropping-an-image-with-python-pil/51703287#51703287). Use the following image and crop the white background:

The desired output image is shown as follows—the bounding rectangle to crop the image is to be found automatically:

3. Use the maximum() and minimum() functions from skimage.filters.rank to implement morphological opening and closing with a grayscale image.