Synology NAS DS112j v18 Administrator's Guide PDF

1

Based on Synology Surveillance Station 9.0.0

License Plate Recognition Administrator's Guide for

Table of Contents

Introduction 01

Quick Camera Installation 01

Position the Camera 03

Ensure Detection Accuracy 04

Detection Accuracy Factors

Image Quality 05

Stroke Width

Minimum Frame Rate

Vehicle Speed

Supported Regions 07

Camera Settings 08

Configure Software Settings 09

Select People & Vehicle Detection

Select a Stream Profile

Enable the License Plate Recognition Function

Manage the License Plate Database 11

Manage Detection Results 12

Alert Settings 13

Export Reports 15

01

Introduction

With its powerful AI Image Analysis, Synology Deep Video Analytics (DVA) can instantly

calculate large amounts of object attributes, filter out environmental interference, and

deliver accurate detection results. Backed with Smart Tag technology and a comprehensive

management interface, it allows users to take control of events with ease and efficiency.

Among the supported algorithms, License Plate Recognition specializes in detecting vehicles

license plates when vehicles have entered a specific area. To accommodate different

scenarios and security levels, you can track and customize your own trigger times.

For you to achieve optimal precision, this guide aims to introduce the key factors of setting

up License Plate Recognition in People and Vehicle Detection tasks. For best results, please

follow the listed points as closely as possible.

System Requirements

Surveillance Station version 9.0.0 or later.

Synologys Deep Learning NVR. (Synology Deep Video Analyticsalso known as DVA

installed by default).

Note: No additional licenses required for People and Vehicle detection.

Introduction

Quick Camera Installation

Step 1

Step 2

Step 3

Select Appropriate Camera 1920x1080@20 FPS or above

300 lux

3 - 10 meters

15 - 30 degrees

25 degrees

25 degrees

7 meters - 20 meters

Stream Quality

Minimum Illumination

Installation Height

Camera Tilt Angle

Horizontal Angle

Camera Roll Angle

Detection Area

Sunshield (Optional) Added to outdoor cameras to avoid direct sunlight on the lens

Check Installation Environment

Mounting Height and Angle

Camera Quick Installation

Camera Quick Installation

03

Position the Camera

Position the Camera

When you mount the camera for License Plate Detection, it is important to get a good, clear

view of the area of interest so the plate can be detected consistently. This ensures accurate

reading and minimizes false detection. The following are methods to best position your

camera:

Avoid objects blocking the camera's field of view such as pillars, barriers, fences, gates, trees,

etc.

Avoid irrelevant moving objects such as people or traffic.

Mount the camera as close as possible to the area of interest.

Adjust the camera angles for optimal detection.

Use the camera's optical zoom, if applicable.

Mount the camera so the license plate appears from the top of the image (or bottom if traffic

is driving away from the camera) instead of from the right or left side. In this way, you make

sure that the recognition process of license plate only starts when the whole plate is in the

view.

04

Ensure Detection Accuracy

A suitable camera placement and envinoment can ensure the detection accuracy. The

following situations can affect detection by the AI:

Light shining directly into the camera's lens may leave streaks in the images or cause

overexposure, affecting the picture quality.

The camera installed in areas where drastic changes in lighting can happen can lead to

inconsistent picture quality.

Overexposed or underexposed license plates images can impede recognition by the AI.

Backgrounds with yellowing lighting can impede recognition by the AI; white lighting is

recommended.

Vehicle moving too fast might cause captured license plates images to blur.

Changes in the cameras field of view might affect the video analytic results (e.g., changes in

focus or zoom level).

Weather sometimes affects the clarity of outdoor cameras. Rain and snow, changes of

shadows, or differences between day and night can have an impact on detection and

recognition.

An unstable network connection might lead to incomplete or corrupt images. Wired

connections are highly recommended.

Dust, insects, or other stains can block the lens. Keep the lenses clean so that a clear image

can be taken.

Slow shutter speed can cause motion blur.

Detection Accuracy Factors

1. Vehicle 2. Physical Surroundings 3. Camera

Speed Lighting conditions Exposure Plare size and position Weather Field of view

Shutter speed Resolution Positioning

Ensure Detection Accuracy

05

Image Quality

A bad image, like motion blur, wil result in lower recognition. Make sure to check your settings

to optimize the image quality.

Stroke Width

A stroke width that is too wide may result in unrecognizable license plates or inaccurate

results. To ensure accurate recognition, the minimum character height must be 30 pixels and

the minimum plate width must be 150 pixels.

Image Quality

06

Image Quality

Minimum Frame Rate

A frame rate that is too low may result in unrecognizable license plates or inaccurate results.

To ensure accurate recognition, the mimimum frame rate must be at least above 20 FPS.

Vehicle Speed

The speed of the vehicle may affect whether the liense plate can be identified correctly.

Depending on the camera specficiations and mounting environments, such as light and

exposure, camera can detect the maximum vehicles speed of 40 km/h.

07

Supported Regions

Supported Regions

We support all license plates that cotain numeric or alphanumeric characters. Select the

following region to get an accurate reading.

Taiwan

Switzerland

Germany

France

United States

08

Camera Settings

Resolution 1080 p or higher

Capture distance 7 - 20m

Mounting height 3 - 10m

Camera orientation - Tilt 15 - 30

Camera orientation - Horizontal 25

Camera orientation - Roll 25

Minimum frame rate 20 FPS

Maximum acceptable traffic speed for successful recognition

40 km/hr

Maximum number of license plates that can be recognized in one frame

4

Minimum charcter height 30 pixels

Minimum plate width 150 pixels

Minimum number of plate characters 4

Maximum number of plate characters 12

Database number 10,000

Match tolerance 2

Two-line plate detection No

Camera Settings

09

Configure Software Settings

Once your cameras are mounted successfully, you can configure software settings for the

DVA to suit your requirements. This chapter covers the essential settings for the License Plate

Recognition.

Select People & Vehicle Detection

To use the License Plate Recognition function, select People & Vehicle Detection as your task

type.

Select a Stream Profile

For optimal detection accuracy, select a resolution of at least 1920x1080@20FPS.

Enable the License Plate Recognition Function

In the Configure detection properties page, tick License plate recogntiion to enable the

relevant function.

Select the specific region to optimize the recognition accuracy.

Configure Software Settings

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Configure Software Settings

Add license plates to the license plate database. Tick Add Allow or Block icons to detection

results to automatically compare license plates in the database with detection results and

matches with Allow or Block.

11

Manage the License Plate Database

You can manage your license plate database from Task > More > Manage License Plate

Database or in the sesttings of the People and Vehicle task.

The database can contain up to a total of 10,000 user-profiles and the license plate can include

4 to 12 Unicode characters.

To create a license plate profile, click Add. Fill in the license plate numbers, choose Allowed or

Block, and add a description.

Manage the License Plate Database

12

Manage Detection Results

Manage Detection Results

Go to Detection Results to mange the license plate results.

If there is a license plate that was detected incorrectly, right-click on the result or click Mark >

Manage license plate labels to edit the license plate.

13

Alert Settings

If you want to receive alarms for Unknown/Allow/Block license plates, go to Monitor Center >

Alert Panel > Alert settings.

Select the device and tick the box to receive alerts for Unknown, Allowed, or Blocked license

plate detected.

Alert Settings

14

Alert Settings

You can find the following alert information in the alert panel:

Date and time

License plate number

Description

Status

15

Export Reports

If you need to manage or analyze the detected vehicles, go to Detection Results > Reports.

Filter your results and export the license plate report.

Export Reports

16

Export Reports

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