pngthumb.php

<?php

/**
 *
 * @category		modules
 * @package			oneforall
 * @author			WBCE Community
 * @copyright		2004-2009, Ryan Djurovich
 * @copyright		2009-2010, Website Baker Org. e.V.
 * @copyright		2019-, WBCE Community
 * @link			https://www.wbce.org/
 * @license			http://www.gnu.org/licenses/gpl.html
 * @platform		WBCE
 *
 */


// Generate a PNG thumbnail from an image
function make_thumb_png($source, $destination, $size) {

	// Check if GD is installed
	if (extension_loaded('gd') AND function_exists('imagecreatefrompng')) {
		// First figure out the size of the thumbnail
		list($original_x, $original_y) = getimagesize($source);
		if ($original_x > $original_y) {
			$thumb_w = $size;
			$thumb_h = $original_y * ($size / $original_x);
		}
		if ($original_x < $original_y) {
			$thumb_w = $original_x * ($size / $original_y);
			$thumb_h = $size;
		}
		if ($original_x == $original_y) {
			$thumb_w = $size;
			$thumb_h = $size;	
		}
		// Now make the thumbnail
		$source  = imagecreatefrompng($source);
		$dst_img = imagecreatetruecolor($thumb_w, $thumb_h);
		// Allow png transparency (full alpha channel information)
		imagealphablending($dst_img, false);
		imagesavealpha($dst_img, true);
		// Resizing
		imagecopyresampled($dst_img, $source, 0,0,0,0, $thumb_w, $thumb_h, $original_x, $original_y);
		imagepng($dst_img, $destination);
		// Clear memory
		imagedestroy($dst_img);
		imagedestroy($source);
		// Return true
		return true;
	} else {
		return false;
	}
}

?>