# How to pass empty kernel to cv2.morphologyEx

**URL:** <https://forum.opencv.org/t/how-to-pass-empty-kernel-to-cv2-morphologyex/6799>\
**Category:** Python\
**Tags:** imgproc\
**Created:** [December 19, 2021, 10:37pm UTC](https://forum.opencv.org/t/how-to-pass-empty-kernel-to-cv2-morphologyex/6799 "2021-12-19T22:37:39Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![chaowenguo](https://avatars.discourse-cdn.com/v4/letter/c/e36b37/32.png) [@chaowenguo](https://forum.opencv.org/u/chaowenguo)\
**Post date:** [December 19, 2021, 10:37pm UTC](https://forum.opencv.org/t/how-to-pass-empty-kernel-to-cv2-morphologyex/6799/1 "2021-12-19T22:37:39Z")

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In opencv java, I can use org.opencv.imgproc.Imgproc.morphologyEx(mat, mat, org.opencv.imgproc.Imgproc.MORPH\_CLOSE, new org.opencv.core.Mat()); to deal with an image and get clear output image (just the main). Now I want to do the same stuff in opencv python: cv2.morphologyEx(img, cv2.MORPH\_CLOSE, ??). I do not know what should be passed to ??. Any help?

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**Author:** ![crackwitz](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/crackwitz/32/14_2.png) [@crackwitz](https://forum.opencv.org/u/crackwitz)\
**Post date:** [December 19, 2021, 11:08pm UTC](https://forum.opencv.org/t/how-to-pass-empty-kernel-to-cv2-morphologyex/6799/2 "2021-12-19T23:08:14Z")

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just pass `None`