# Reading text or plate numbers from an RTSP camera in a flow: what do you use?

**URL:** <https://discourse.nodered.org/t/reading-text-or-plate-numbers-from-an-rtsp-camera-in-a-flow-what-do-you-use/102034>\
**Category:** General\
**Created:** [1 November 2026 03:11 UTC](https://discourse.nodered.org/t/reading-text-or-plate-numbers-from-an-rtsp-camera-in-a-flow-what-do-you-use/102034 "2026-11-01T03:11:08Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![VisuDock](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/visudock/32/108796_2.png) [@VisuDock](https://discourse.nodered.org/u/VisuDock)\
**Post date:** [1 November 2026 03:11 UTC](https://discourse.nodered.org/t/reading-text-or-plate-numbers-from-an-rtsp-camera-in-a-flow-what-do-you-use/102034/1 "2026-11-01T03:11:08Z")

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Hi all. I am curious how people here get text or numbers out of a camera feed inside Node-RED.

The use cases I keep hearing about: a number on an old machine display, a plate at a gate or car park, a label on a box.

What I have seen so far:

- grab a snapshot with an http request or ffmpeg, then call Tesseract or another OCR service
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  - send the snapshot to a cloud AI and parse the answer

- 
  - run a separate program and push the result into Node-RED over MQTT  
Questions:

- What do you use, and does it run fully local?
- 
  - How do you deal with a bad picture (glare, night, blur)? Do you fix it at the camera or in software?

- 
  - How often do you grab a frame, and how do you stop reading the same thing twice?  
Disclosure so nobody is surprised: I make a Windows program called VisuDock Live OCR that reads text and plates from camera feeds, so I am biased. I am not selling anything here. I just want to learn what real setups look like and what is annoying about them.

Thanks!

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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:** [2 November 2026 14:06 UTC](https://discourse.nodered.org/t/reading-text-or-plate-numbers-from-an-rtsp-camera-in-a-flow-what-do-you-use/102034/2 "2026-11-02T14:06:52Z")

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I did, several years ago, some experimental stuff running a Python script using cv2 & MobileNetSSD (cv2.dnn.readNetFromCaffe("MobileNetSSD\_lpr.prototxt","lpr.caffemodel")

It worked ok but since I do not really need such a solution I stopped looking further. I expect that today you should have much better libraries, models and computer power available. From the perspective of object detection I think YOLO is totally outstanding compared to the rest. It should however run on a computer with lot of GPU power (i.e. Nvidia). If there are already made models for license plates I do not know

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**Author:** ![VisuDock](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/visudock/32/108796_2.png) [@VisuDock](https://discourse.nodered.org/u/VisuDock)\
**Post date:** [3 November 2026 06:15 UTC](https://discourse.nodered.org/t/reading-text-or-plate-numbers-from-an-rtsp-camera-in-a-flow-what-do-you-use/102034/3 "2026-11-03T06:15:34Z")

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Thanks for the reply, that is useful. YOLO is a good fit for finding the plate in the picture. One thing to keep in mind: it only gives you a box around the plate, not the characters. You still need a second step that reads the letters from the cropped box, for example a small OCR model, or Tesseract limited to capital letters and digits.

Plate detectors are usually small models, so for a single gate camera a big Nvidia card is often not needed if you only look at a frame every few hundred milliseconds.

Out of curiosity, did your old script read the characters as well, or did it only find the plate?

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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:** [3 November 2026 06:58 UTC](https://discourse.nodered.org/t/reading-text-or-plate-numbers-from-an-rtsp-camera-in-a-flow-what-do-you-use/102034/4 "2026-11-03T06:58:20Z")

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> [@VisuDock](#):
>
> did your old script read the characters as well

Yes, I had a table with allowed LP's that it checked