使用方法： 将该文件存放在任何php环境。运行方法两种： 1. 命令行模式 php resizeimage.php {path} 2. 浏览器模式 localhost/resizeimage.php?path=. 注意路径最好使用相对路径

resizeimage.php

<?php

$dir = '';
if (isset($argv[1])) $dir = $argv[1];

if ($_REQUEST['path']) $dir = $_REQUEST['path'];

if (!$dir) {
	echo "Path not specified! Please use `localhost/resizeimage.php?path=.` or `php resizeimage.php {path}`\n";exit;
}

runindir($dir);

function resize($img, $newfilename, $w='', $h='') {

	//Check if GD extension is loaded
	if (!extension_loaded('gd') && !extension_loaded('gd2')) {
		trigger_error("GD is not loaded", E_USER_WARNING);
		return false;
	}

	//Get Image size info
	list($width, $height) = getimagesize($img);
	if (!$w) $w = $width / 2;
	if (!$h) $h = $height / 2;
	$imgInfo = getimagesize($img);
	switch ($imgInfo[2]) {
		case 1:
			$im = imagecreatefromgif($img);
			break;
		case 2:
			$im = imagecreatefromjpeg($img);
			break;
		case 3:
			$im = imagecreatefrompng($img);
			break;
		default:
			trigger_error('Unsupported filetype!', E_USER_WARNING);
			break;
	}

	//If image dimension is smaller, do not resize
	if ($imgInfo[0] <= $w && $imgInfo[1] <= $h) {
		$nHeight = $imgInfo[1];
		$nWidth = $imgInfo[0];
	} else {
		//yeah, resize it, but keep it proportional
		if ($w / $imgInfo[0] > $h / $imgInfo[1]) {
			$nWidth = $w;
			$nHeight = $imgInfo[1] * ($w / $imgInfo[0]);
		} else {
			$nWidth = $imgInfo[0] * ($h / $imgInfo[1]);
			$nHeight = $h;
		}
	}
	$nWidth = round($nWidth);
	$nHeight = round($nHeight);

	$newImg = imagecreatetruecolor($nWidth, $nHeight);

	/* Check if this image is PNG or GIF, then set if Transparent*/
	if (($imgInfo[2] == 1) OR($imgInfo[2] == 3)) {
		imagealphablending($newImg, false);
		imagesavealpha($newImg, true);
		$transparent = imagecolorallocatealpha($newImg, 255, 255, 255, 127);
		imagefilledrectangle($newImg, 0, 0, $nWidth, $nHeight, $transparent);
	}
	imagecopyresampled($newImg, $im, 0, 0, 0, 0, $nWidth, $nHeight, $imgInfo[0], $imgInfo[1]);

	//Generate the file, and rename it to $newfilename
	switch ($imgInfo[2]) {
		case 1:
			imagegif($newImg, $newfilename);
			break;
		case 2:
			imagejpeg($newImg, $newfilename);
			break;
		case 3:
			imagepng($newImg, $newfilename);
			break;
		default:
			trigger_error('Failed resize image!', E_USER_WARNING);
			break;
	}

	return $newfilename;
}


function runindir($dir) {
	if (is_dir($dir)) {
		if ($dh = opendir($dir)) {
			while (($file = readdir($dh)) !== false) {
				if ($pos = strpos($file, '_2x.')) {
					$name = substr($file, 0, $pos);
					$type = substr($file, $pos+4);
					$new_filename = $dir.'/'.$name.'.'.$type;
					echo resize($dir.'/'.$file, $new_filename)."\n";
				}
			}
			closedir($dh);
		}
	}
}