✨ init from https://github.com/codemasher/php-qrcode-decoder/commit/5798a53268f14eb1d7d70098d23db0a81b25f98b

src/Decoder/GDLuminanceSource.php

@@ -0,0 +1,71 @@
+<?php
+/**
+ * Class GDLuminanceSource
+ *
+ * @created      17.01.2021
+ * @author       ZXing Authors
+ * @author       Smiley <smiley@chillerlan.net>
+ * @copyright    2021 Smiley
+ * @license      Apache-2.0
+ *
+ *  @noinspection PhpComposerExtensionStubsInspection
+ */
+
+namespace chillerlan\QRCode\Decoder;
+
+use InvalidArgumentException;
+use function get_resource_type, imagecolorat, imagecolorsforindex, imagesx, imagesy, is_resource;
+use const PHP_MAJOR_VERSION;
+
+/**
+ * This class is used to help decode images from files which arrive as GD Resource
+ * It does not support rotation.
+ */
+final class GDLuminanceSource extends LuminanceSource{
+
+	/**
+	 * @var resource|\GdImage
+	 * @phan-suppress PhanUndeclaredTypeProperty
+	 */
+	private $gdImage;
+
+	/**
+	 * GDLuminanceSource constructor.
+	 *
+	 * @param resource|\GdImage $gdImage
+	 * @phan-suppress PhanUndeclaredTypeParameter
+	 *
+	 * @throws \InvalidArgumentException
+	 */
+	public function __construct($gdImage){
+
+		/**
+		 * @noinspection PhpElementIsNotAvailableInCurrentPhpVersionInspection
+		 * @phan-suppress PhanUndeclaredClassInstanceof
+		 */
+		if(
+			(PHP_MAJOR_VERSION >= 8 && !$gdImage instanceof \GdImage)
+			|| (PHP_MAJOR_VERSION < 8 && (!is_resource($gdImage) || get_resource_type($gdImage) !== 'gd'))
+		){
+			throw new InvalidArgumentException('Invalid GD image source.');
+		}
+
+		parent::__construct(imagesx($gdImage), imagesy($gdImage));
+
+		$this->gdImage = $gdImage;
+
+		$this->setLuminancePixels();
+	}
+
+	private function setLuminancePixels():void{
+		for($j = 0; $j < $this->height; $j++){
+			for($i = 0; $i < $this->width; $i++){
+				$argb  = imagecolorat($this->gdImage, $i, $j);
+				$pixel = imagecolorsforindex($this->gdImage, $argb);
+
+				$this->setLuminancePixel($pixel['red'], $pixel['green'], $pixel['blue']);
+			}
+		}
+	}
+
+}