---
version: "V9.7"
language: "en"
---
# LPR Camera Installation tips

## It is recommended to install the camera in the center of the vehicle

![1.jpg](https://documentation.mirasys.com/__attachments/a_52d5604660d5038c4a0f014d4d960223ea158aa9e461f54ba34f5a2a6f612f1f/1.jpg?cb=98b9292155d92d084e6268525ecf2829)

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### If the camera is installed on the side of the road or lane, the angle should not exceed 30 degrees.

![2.jpg](https://documentation.mirasys.com/__attachments/a_562d32e1e6f78de5a0a5fdda1678eff0ea45168b7f226bc80dbbfa243d537e7d/2.jpg?cb=ee602aa854703ced00b6b2db91e5b716)

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#### The camera should be installed higher than the vehicle headlights so that the vehicle's headlights don't point directly at the camera

![3.jpg](https://documentation.mirasys.com/__attachments/a_abb1bdab156e47aa5003a4d17e73842f79dbff4e7096cb8b5a3ae58f436a22fd/3.jpg?cb=cbadf8ba0a0d7d5a5a329d9a796e5215)

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#### Ensure the license plate width is at least 120 pixels and height at least 50 pixels

![att_1_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_4c4c83432c1057b86392056bddf9b5054bd47e2202ea197dd1e251b46ea4973f/att_1_for_2037187729.jpeg?cb=c1322a55328fd1858245d712f2195aba)

Height at least 50 pixels

Width at least 120 pixels

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#### License plate tilt angle must be within +/- 10 degrees

![att_2_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_e005b1b38903327017dabb6650c9cd4eb1b732b58143742c621841cee162ecf4/att_2_for_2037187729.jpeg?cb=665e50fa6fdee64fcd0852fdd951333a)

![att_3_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_7aea6a04899ec34053fa858367439cd6c6d24d046712cc99ff8aadd8a3f0dc9e/att_3_for_2037187729.jpeg?cb=b6d723f87e20e0fce9970e39ed16a224)

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## LPR settings in the System Manager application

Ensure the correct region (Americas / Eurasia) is selected.

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### Setting the region of interest

Region of interest is used to define where detection will find license plates.  
![att_14_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_81a023202ef3b821cdf150ce228a1a4ed836db1fb85301447ad2d29b1816d0d8/att_14_for_2037187729.jpeg?cb=5bc144b0f372e521d72fa341302363bf)

Leave some margin to the region of interest to not detect partially visible plates.

![att_15_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_5d569bfcbddf11ae117e870a9bd362b0651a854fa7845746c6c247d249efe91a/att_15_for_2037187729.jpeg?cb=2a86f31e5cda050487fd534fb420e031)

The whole license plate is inside the region of interest, and the plate is detected.

![att_16_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_259c5eda59f8b43b596ad51411e144b2166210e235ae85da8661aa0206f2d385/att_16_for_2037187729.jpeg?cb=3f4b7faaaeaa330d0fffe08674ae4656)

The license plate is not completely inside the region of interest, and the plate is not detected.

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### Enabling country recognition

In many countries letter **O** is similar to the number **0** , and the letter **I** looks the same as the number **1**. Enabling country detection improves detection accuracy in these cases.  
![att_4_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_1058ec93b1fed773b62d21ab30a1f50ee177330e347da6913f2dea99d98b07a8/att_4_for_2037187729.jpeg?cb=31af2d5ff3bd99714cbe8e4c029b0357)

For example, the format for Brazil plate number is "abc1d23".

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## Common problems and solutions

### Incomplete license plate

![att_5_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_bf2fa09a1c79a9c6f16e1e48b92b0c11fc7d6e79c1c6247dc10e5579c2618667/att_5_for_2037187729.jpeg?cb=3e604ad1a66bfcdc19898114a9906786)

Solution: Don't set the region of interest too close to image borders.

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### View angle makes plate numbers unreadable

![att_6_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_55fabb400e41f1345f411702d02416fbfe72523eafb71f4ca4e76a2066e5986e/att_6_for_2037187729.jpeg?cb=afe3ac95f7187176c51a61c3a6fb31df)

Solution 1: Move the camera to a better place.

Solution 2: Set the region of interest so that the plate is detected when it is visible from better angle.

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### Other vehicles headlights reflect from license plate

![att_7_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_9ef96e7ffb4ac9459560ad5cf3097b61ee268cdc7a5db1503edf7f2a3ab44715/att_7_for_2037187729.jpeg?cb=8a226f21fe256c16a36d57023e1807a4)

Solution 1: Move the camera to a better place.

Solution 2: Set the region of interest so that the plate is detected when other vehicles' headlights don't point to the license plate direction.

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### The license plate is too small

![att_8_for_2037187729.png](https://documentation.mirasys.com/__attachments/a_dada00e90638cff2ce534f82882cde8c67022833534b3bc32dae8d85cc372aa7/att_8_for_2037187729.png?cb=b9c571ebe556c89f2b0546b039493d52)

Solution 1: Move the camera to a better place or zoom in.

Solution 2: Set the region of interest so that the plate is detected when the vehicle is nearer to the camera.

Solution 3: Increase the minimum plate height value in LPR settings so that small plate detections are ignored.

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### The license plate is blurry

![att_9_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_dae437c8a5c1460bc8efa1f2243ddf5a7920a215d000385d528638b1c014e238/att_9_for_2037187729.jpeg?cb=26b666f3972d3b0a6d7a9458bfa4240c)

Solution 1: Adjust sharpness and increase shutter speed in the camera's settings.

Solution 2: Increase the lighting of the area.

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### The license plate is overexposed

![att_10_for_2037187729.jpeg](https://documentation.mirasys.com/__attachments/a_a995e3a802d367b26b1c8e51563d15cf14cd6ce59b0fe6fb5cdb6d130977a592/att_10_for_2037187729.jpeg?cb=6029bebd17abdb268581aa8a118509e5)

Solution 1: Adjust camera's image settings.

Solution 2: Check the camera installation location and move it higher so that headlights doesn't reflect from the plate.

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