cli-barcode/vendor/picqer/php-barcode-generator/examples.php

<?php

include('src/BarcodeGenerator.php');
include('src/BarcodeGeneratorPNG.php');
include('src/BarcodeGeneratorSVG.php');
include('src/BarcodeGeneratorHTML.php');

$generatorPNG = new Picqer\Barcode\BarcodeGeneratorPNG();
$generatorSVG = new Picqer\Barcode\BarcodeGeneratorSVG();
$generatorHTML = new Picqer\Barcode\BarcodeGeneratorHTML();

echo $generatorHTML->getBarcode('081231723897', $generatorPNG::TYPE_CODE_128);
echo $generatorSVG->getBarcode('081231723897', $generatorPNG::TYPE_EAN_13);
echo '<img src="data:image/png;base64,' . base64_encode($generatorPNG->getBarcode('081231723897', $generatorPNG::TYPE_CODE_128)) . '">';