<?php
declare(strict_types=1);

$image = imagecreatetruecolor(2, 2);
imagealphablending($image, false);
imagesavealpha($image, true);
$clear = imagecolorallocatealpha($image, 0, 0, 0, 127);
imagefill($image, 0, 0, $clear);
imagepng($image, "clear.png");
$loaded = imagecreatefrompng("clear.png");
echo imagecolorsforindex($loaded, imagecolorat($loaded, 0, 0))["alpha"], "\n";
