# Flow needed for image recognition

**URL:** <https://discourse.nodered.org/t/flow-needed-for-image-recognition/99789>\
**Category:** General\
**Created:** [27 November 2025 20:18 UTC](https://discourse.nodered.org/t/flow-needed-for-image-recognition/99789 "2025-11-27T20:18:37Z")\
**Posts on this page:** 5\
**Page:** 2

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**Author:** ![krambriw](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/krambriw/32/5429_2.png) [@krambriw](https://discourse.nodered.org/u/krambriw)\
**Post date:** [4 December 2025 14:25 UTC](https://discourse.nodered.org/t/flow-needed-for-image-recognition/99789/23 "2025-12-04T14:25:11Z")

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Or make an external python script that compares two images, one with empty tray and one when there is something on it

Just one Q; doesn't the printer have an api that tells you when a printing has finished??

> <https://stackoverflow.com/questions/72851122/how-to-compare-how-similar-two-images-are-in-python/72967223#72967223>

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**Author:** ![cymplecy](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/cymplecy/32/2773_2.png) [@cymplecy](https://discourse.nodered.org/u/cymplecy)\
**Post date:** [4 December 2025 15:09 UTC](https://discourse.nodered.org/t/flow-needed-for-image-recognition/99789/24 "2025-12-04T15:09:42Z")

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Could I suggest reading my 1st post? 🙂

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**Author:** ![krambriw](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/krambriw/32/5429_2.png) [@krambriw](https://discourse.nodered.org/u/krambriw)\
**Post date:** [4 December 2025 15:26 UTC](https://discourse.nodered.org/t/flow-needed-for-image-recognition/99789/25 "2025-12-04T15:26:06Z")

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I don't think your 1st post gives any additional information in respect to given suggestions and my question:

- does your printer have an api that reports printing statuses?

If not I still suggest you do image comparison in some way, maybe outside of NR if preferable, unless you would see a better option in adding some sort of sensors to your printer

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**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [4 December 2025 16:23 UTC](https://discourse.nodered.org/t/flow-needed-for-image-recognition/99789/26 "2025-12-04T16:23:04Z")

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> [@krambriw](#):
>
> If not I still suggest you do image comparison in some way

Assuming it is like mine, the bed can be manually moved while not in use, so the bed itself will not always be in the same position.

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**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/nodered/original/1X/d073cd938eafa2e558d7c2cd59003b3ef4963033.png) [@system](https://discourse.nodered.org/u/system)\
**Post date:** [4 March 2026 16:23 UTC](https://discourse.nodered.org/t/flow-needed-for-image-recognition/99789/27 "2026-03-04T16:23:10Z")

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