lychee/php/helpers/fastImageCopyResampled.php

<?php

function fastImageCopyResampled(&$dst_image, $src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h, $quality = 4) {

	/**
	 * Plug-and-Play fastImageCopyResampled function replaces much slower imagecopyresampled.
	 * Just include this function and change all "imagecopyresampled" references to "fastImageCopyResampled".
	 * Typically from 30 to 60 times faster when reducing high resolution images down to thumbnail size using the default quality setting.
	 * Author: Tim Eckel - Date: 09/07/07 - Version: 1.1 - Project: FreeRingers.net - Freely distributable - These comments must remain.
	 *
	 * Optional "quality" parameter (defaults is 3). Fractional values are allowed, for example 1.5. Must be greater than zero.
	 * Between 0 and 1 = Fast, but mosaic results, closer to 0 increases the mosaic effect.
	 * 1 = Up to 350 times faster. Poor results, looks very similar to imagecopyresized.
	 * 2 = Up to 95 times faster.  Images appear a little sharp, some prefer this over a quality of 3.
	 * 3 = Up to 60 times faster.  Will give high quality smooth results very close to imagecopyresampled, just faster.
	 * 4 = Up to 25 times faster.  Almost identical to imagecopyresampled for most images.
	 * 5 = No speedup. Just uses imagecopyresampled, no advantage over imagecopyresampled.
	 */

	if (empty($src_image) || empty($dst_image) || $quality <= 0) { return false; }

	if ($quality < 5 && (($dst_w * $quality) < $src_w || ($dst_h * $quality) < $src_h)) {

		$temp = imagecreatetruecolor($dst_w * $quality + 1, $dst_h * $quality + 1);
		imagecopyresized($temp, $src_image, 0, 0, $src_x, $src_y, $dst_w * $quality + 1, $dst_h * $quality + 1, $src_w, $src_h);
		imagecopyresampled($dst_image, $temp, $dst_x, $dst_y, 0, 0, $dst_w, $dst_h, $dst_w * $quality, $dst_h * $quality);
		imagedestroy($temp);

	} else imagecopyresampled($dst_image, $src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h);

	return true;

}

?>