# blob region

**URL:** https://forums.openmv.io/t/blob-region/1859
**Category:** OpenMV Boards
**Created:** [August 3, 2020, 11:49am UTC](https://forums.openmv.io/t/blob-region/1859 "2020-08-03T11:49:43Z")
**Posts on this page:** 5
**Page:** 1

<div class="post-metadata">

### Author: ![oramafanis](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/oramafanis/32/1783_2.png) [@oramafanis](https://forums.openmv.io/u/oramafanis)
#### Post date: [August 3, 2020, 11:49am UTC](https://forums.openmv.io/t/blob-region/1859/1 "2020-08-03T11:49:43Z")

</div>

Hi there,

i was wondering if it is possible to use an area of a blob as region of another blob.  
I don’t mean the rectangle that outputs but the exact area of a blob so to find blobs of other color inside it.

---

<div class="post-metadata">

### Author: ![kwagyeman](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/kwagyeman/32/4_2.png) [@kwagyeman](https://forums.openmv.io/u/kwagyeman)
#### Post date: [August 3, 2020, 3:33pm UTC](https://forums.openmv.io/t/blob-region/1859/2 "2020-08-03T15:33:04Z")

</div>

Hi, do you have an example image where just calling find\_blobs() again on the roi of the previously found blob doesn’t give you what you need followed by some filtering?

---

<div class="post-metadata">

### Author: ![oramafanis](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/oramafanis/32/1783_2.png) [@oramafanis](https://forums.openmv.io/u/oramafanis)
#### Post date: [August 7, 2020, 7:25am UTC](https://forums.openmv.io/t/blob-region/1859/3 "2020-08-07T07:25:36Z")

</div>

hi friend!

i will manage to do some filtering to get my result for sure.

in this picture i want to count only the white blobs inside the big black circle blob for example.

![](https://canada1.discourse-cdn.com/flex029/uploads/openmv1/original/2X/1/11d777cb0bd04624c426fcc63dc4ae606518f0eb.jpeg)

can i use other regions except the rectangle?

---

<div class="post-metadata">

### Author: ![kwagyeman](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/kwagyeman/32/4_2.png) [@kwagyeman](https://forums.openmv.io/u/kwagyeman)
#### Post date: [August 7, 2020, 5:37pm UTC](https://forums.openmv.io/t/blob-region/1859/4 "2020-08-07T17:37:47Z")

</div>

Just check if the little blobs rect intersects with the big blobs circle.

> <https://stackoverflow.com/questions/401847/circle-rectangle-collision-detection-intersection>

If you want a more general answer for any object… then I don’t think we can do that as find\_blobs() doesn’t keep the contour of the blob for memory reasons.

---

<div class="post-metadata">

### Author: ![oramafanis](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/oramafanis/32/1783_2.png) [@oramafanis](https://forums.openmv.io/u/oramafanis)
#### Post date: [August 8, 2020, 7:02pm UTC](https://forums.openmv.io/t/blob-region/1859/5 "2020-08-08T19:02:53Z")

</div>

Thank you …