# How can find these two circles?

**URL:** <https://forum.opencv.org/t/how-can-find-these-two-circles/4672>\
**Category:** C++\
**Tags:** imgproc\
**Created:** [August 9, 2021, 6:03am UTC](https://forum.opencv.org/t/how-can-find-these-two-circles/4672 "2021-08-09T06:03:26Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![wulicheng](https://avatars.discourse-cdn.com/v4/letter/w/9de053/32.png) [@wulicheng](https://forum.opencv.org/u/wulicheng)\
**Post date:** [August 9, 2021, 6:03am UTC](https://forum.opencv.org/t/how-can-find-these-two-circles/4672/1 "2021-08-09T06:03:26Z")

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![20210809111031](https://us1.discourse-cdn.com/flex020/uploads/opencv/original/2X/0/08ba56f2ee1aff2dd6097492fcded4b9bb1da7c9.png)  
picture 1  
 ![20210809111031](https://us1.discourse-cdn.com/flex020/uploads/opencv/original/2X/0/06cf715c395230b52d0bfec060626a408c4facee.png)  
picture 2

Can anyone give me some suggestions for in the picture 1 find circles like the picture 2 automatically.  
In factor it like this:

 ![image](https://us1.discourse-cdn.com/flex020/uploads/opencv/original/2X/a/ac9e0b2feb69062f135c849c62ff1470fffb1783.png)

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<div class="post-metadata">

**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:** [August 9, 2021, 3:21pm UTC](https://forum.opencv.org/t/how-can-find-these-two-circles/4672/2 "2021-08-09T15:21:23Z")

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inscribed circles?

apply a distance transform with L2 norm (euclidean distance)