Transparent Circular Crop using PHP GD

In this article, I will show how to crop an image to transparent circular image using PHP GD Library.

What is GD Library?

The GD library is a graphics drawing library that provides tools for manipulating image data. The GD library is used to process images for generating gallery preview and thumbnail size images automatically.

The image functions in PHP GD library can be used to work with the image files.

Example of PNG Creation with PHP:

<?php

header("Content-type: image/png");
$string = $_GET['text'];
$im     = imagecreatefrompng("images/button1.png");
$orange = imagecolorallocate($im, 220, 210, 60);
$px     = (imagesx($im) - 7.5 * strlen($string)) / 2;
imagestring($im, 3, $px, 9, $string, $orange);
imagepng($im);
imagedestroy($im);

?>

Transparent Circular Crop

Simple PHP Script to crop an image to transparent circular image:

<?php 

$filename = "images/".$_GET['image'].".jpg";
$image_s = imagecreatefromstring(file_get_contents($filename));
$width = imagesx($image_s);
$height = imagesy($image_s);

$newwidth = 285;
$newheight = 285;

$image = imagecreatetruecolor($newwidth, $newheight);
imagealphablending($image, true);
imagecopyresampled($image, $image_s, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);

//create masking
$mask = imagecreatetruecolor($newwidth, $newheight);

$transparent = imagecolorallocate($mask, 255, 0, 0);
imagecolortransparent($mask,$transparent);

imagefilledellipse($mask, $newwidth/2, $newheight/2, $newwidth, $newheight, $transparent);

$red = imagecolorallocate($mask, 0, 0, 0);
imagecopymerge($image, $mask, 0, 0, 0, 0, $newwidth, $newheight, 100);
imagecolortransparent($image,$red);
imagefill($image, 0, 0, $red);

//output, save and free memory
header('Content-type: image/png');
imagepng($image);
imagepng($image,'output.png');
imagedestroy($image);
imagedestroy($mask);

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For full instructions and code,  you can follow this video: