NuGet Package SimpleLPR License Plate Recognition (LPR/ANPR) library.

SimpleLPR is a software component for vehicle license plate recognition.

It has a very simple programming interface that allows applications to supply a path to an image or a buffer in memory and return the detected license plate text and its location in the input image. It can be used from C++, .NET-enabled programming languages, or Python. Integration is simple and straightforward, as demonstrated by the examples provided with the SDK. Typical detection rates range between 85% and 95%, provided the license plates are in good condition, free of obstructions, and the text height is at least 20 pixels.

You can download the user's guide from, and the class reference for .NET from

Please submit questions/issues/bug reports/feedback to

Code example:

using System;
using System.Collections.Generic;
using SimpleLPR3;

// Create an instance of the SimpleLPR engine
EngineSetupParms setupP;
setupP.cudaDeviceId = -1; // Select CPU
setupP.enableImageProcessingWithGPU = false;
setupP.enableClassificationWithGPU = false;
setupP.maxConcurrentImageProcessingOps = 0; // Use the default value

// Create the SimpleLPR engine
ISimpleLPR lpr = SimpleLPR.Setup(setupP);

// Enable country templates for Brazil
lpr.set_countryWeight("Brazil", 1.0f);
lpr.set_countryWeight(countryId, 1.0f);

// Create a processor object
IProcessor proc = lpr.createProcessor();

// Use the analyze version that takes the path to a file
List<Candidate> cds = proc.analyze("image.jpg");

// Iterate over all candidates
foreach (Candidate cd in cds)
// Iterate over all country matches
foreach (CountryMatch match in cd.matches)
Console.WriteLine("Text: {0}, country: {1}", match.text,;


Version: 3.5.3
Author(s): Tony
Last Update: Tuesday, March 14, 2023
.NET Fiddle: Create the first Fiddle
Project Url:
NuGet Url:

Install-Package SimpleLPR
dotnet add package SimpleLPR
paket add SimpleLPR
SimpleLPR Download (Unzip the "nupkg" after downloading)