# Add reacts to black better than white color

**URL:** <https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930>\
**Category:** Uncategorized\
**Created:** [December 21, 2023, 10:22pm UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930 "2023-12-21T22:22:43Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![kakcalu13](https://avatars.discourse-cdn.com/v4/letter/k/bc8723/32.png) [@kakcalu13](https://forum.opencv.org/u/kakcalu13)\
**Post date:** [December 21, 2023, 10:22pm UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930/1 "2023-12-21T22:22:43Z")

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I don’t get how this impacts heavily based on `add()`. See the example below:  
Original image

 ![0-1-0](https://us1.discourse-cdn.com/flex020/uploads/opencv/original/2X/4/43fd81ec51c8b96bd82af6346e383f5354d4d3a4.png)

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**Author:** ![kakcalu13](https://avatars.discourse-cdn.com/v4/letter/k/bc8723/32.png) [@kakcalu13](https://forum.opencv.org/u/kakcalu13)\
**Post date:** [December 21, 2023, 10:23pm UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930/2 "2023-12-21T22:23:19Z")

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![0-2-0](https://us1.discourse-cdn.com/flex020/uploads/opencv/original/2X/9/9b99a33b07bb13114c2c300eaa846b0170467573.png)

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<div class="post-metadata">

**Author:** ![kakcalu13](https://avatars.discourse-cdn.com/v4/letter/k/bc8723/32.png) [@kakcalu13](https://forum.opencv.org/u/kakcalu13)\
**Post date:** [December 21, 2023, 10:23pm UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930/3 "2023-12-21T22:23:52Z")

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**difference after** `difference = cv2.add(previous, current)`  
 ![image](https://us1.discourse-cdn.com/flex020/uploads/opencv/original/2X/d/dae41d612184762f2d1525bdb3a27a89db12dc9b.png)

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<div class="post-metadata">

**Author:** ![kakcalu13](https://avatars.discourse-cdn.com/v4/letter/k/bc8723/32.png) [@kakcalu13](https://forum.opencv.org/u/kakcalu13)\
**Post date:** [December 21, 2023, 10:24pm UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930/4 "2023-12-21T22:24:24Z")

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So when I did white, See here:

 ![0-1-0](https://us1.discourse-cdn.com/flex020/uploads/opencv/original/2X/3/367f5b87d8862b0d0426273235468f2c5cf56bac.png)

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<div class="post-metadata">

**Author:** ![kakcalu13](https://avatars.discourse-cdn.com/v4/letter/k/bc8723/32.png) [@kakcalu13](https://forum.opencv.org/u/kakcalu13)\
**Post date:** [December 21, 2023, 10:25pm UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930/5 "2023-12-21T22:25:00Z")

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![0-2-0](https://us1.discourse-cdn.com/flex020/uploads/opencv/original/2X/d/d8fc5b8735a025117f7a2f33c4a9b69881b4f72b.png)

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<div class="post-metadata">

**Author:** ![kakcalu13](https://avatars.discourse-cdn.com/v4/letter/k/bc8723/32.png) [@kakcalu13](https://forum.opencv.org/u/kakcalu13)\
**Post date:** [December 21, 2023, 10:25pm UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930/6 "2023-12-21T22:25:31Z")

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which result as this:  
 ![image](https://us1.discourse-cdn.com/flex020/uploads/opencv/original/2X/2/2437ca20a8a287334a16026a16bc8297a30c2fc9.png)

How come there’s 5 types to compare the frame when I just want to detect the difference without any extra?

If this is duplicate topic, could you kindly share the link?

Thank you so much for your time too!

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<div class="post-metadata">

**Author:** ![kakcalu13](https://avatars.discourse-cdn.com/v4/letter/k/bc8723/32.png) [@kakcalu13](https://forum.opencv.org/u/kakcalu13)\
**Post date:** [December 21, 2023, 10:26pm UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930/7 "2023-12-21T22:26:15Z")

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Sorry for multiple replies. This website won’t let me upload 6 pictures in one topic due to new member. I understand though

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**Author:** ![berak](https://avatars.discourse-cdn.com/v4/letter/b/85f322/32.png) [@berak](https://forum.opencv.org/u/berak)\
**Post date:** [December 22, 2023, 5:50am UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930/9 "2023-12-22T05:50:24Z")

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> [@kakcalu13](#):
>
> difference = cv2.add(previous, current)

ouch. (it hurts already, reading this)

you have _binary_ images here. boolean logic applies.  
(rather think: a OR b, instead of ‘+’)

white+white=white;  
white+black=white;  
black+black=black

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<div class="post-metadata">

**Author:** ![kakcalu13](https://avatars.discourse-cdn.com/v4/letter/k/bc8723/32.png) [@kakcalu13](https://forum.opencv.org/u/kakcalu13)\
**Post date:** [December 22, 2023, 4:18pm UTC](https://forum.opencv.org/t/add-reacts-to-black-better-than-white-color/15930/10 "2023-12-22T16:18:15Z")

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damn, ill go back and read doc again. thank you!

Is there any that just return the difference only? like

```auto
previous frame: [[30, 20, 10], [30, 20, 50]] 
current frame: [[30, 20, 10], [30, 20, 30]]

returns [30, 20, 30]

```