Camel OpenALPR component

Camel OpenALPR component relies on the OpenALPR library to perform image recognition of the incoming binary data in order to find and read license plates.

Maven dependency

Maven users should add the following dependency to their POM file:


Available for rhiot.version >= 0.1.4

URI format


Where label can be replaced with any text label:


This routes the input stream from the webcam to the OpenALPR component. The results of the scanning are represented as a list of io.rhiot.cloudplatform.camel.openalpr.PlateMatch:

import io.rhiot.cloudplatform.camel.openalpr.PlateMatch;
InputStream image = ...;
List<PlateMatch> matches = producerTemplate.requestBody("openalpr:plateScanner", image, List.class);
PlateMatch bestMatch = matches.get(0);
String plateNumer = bestMatch.getPlateNumber();
double matchConfidenceInPercent = bestMatch.getConfidence();

Dockerized OpenALPR

By default this component relies on a dockerized version of the OpenALPR. It means that you should have Docker shell client installed and configured.

You can change the system command used by the component to invoke OpenALPR, by setting the commandStrategy option on the endpoint and referencing custom io.rhiot.cloudplatform.camel.openalpr.OpenalprCommandStrategy instance:

OpenalprCommandStrategy myCommand() {
    return new OpenalprCommandStrategy(){
        String[] openalprCommand(OpenalprEndpoint openalprEndpoint, File imageFile) {
            return new String[]{"alpr", "-c", "eu", imageFile.getName()};



URI Options Parameters

Option Default value Description
country eu Country class of the plates used by DockerizedOpenalprCommandStrategy. Can be eu or us.
workDir /tmp/openalpr-workdir Working directory used by OpenALPR to temporarily store files for the analysis.
processManager new io.rhiot.utils.process. DefaultProcessManager io.rhiot.utils.process.ProcessManager instance used to execute OpenALPR command.
commandStrategy new io.rhiot.cloudplatform. camel.openalpr. DockerizedOpenalprCommandStrategy io.rhiot.cloudplatform. camel.openalpr. OpenalprCommandStrategy instance used to generate OpenALPR system command.
dockerImage rhiot/openalpr:0.1.4-SNAPSHOT Docker image used by DockerizedOpenalprCommandStrategy.