erode/dilte - without shifting the image downwards

Question

I eroded an image and then dilated it.

im = cv.erode(im, (7,7), iterations=5)
im = cv.dilate(im, (7,7), iterations=5)

This is the original images

And this is the eroded-then-dilated image

I tried to remove the small portion on the top-right of the original image which was removed properly. But the new image is shifted slightly downward compared to the original image. Is there any way to erode and dilate without shifting the image downward?

Answer 1

Finally fixed it. It was easy. Just rotated the image 180 degrees before dilating again. Then rotated it 180 degrees again after dilation

Answer 2

Your code should not have worked at all. Your second argument is wrong. It must be a kernel (2D array), not the size of the kernel.

Simply pass None there. That will assume a simple 3x3 box kernel. Then work with the iterations argument.

You should work more closely with the documentation .