PHP adjust image width and height example sharing

/** * 改变图片的宽高 * * @author flynetcn (2009-12-16) * * @param string $img_src 原图片的存放地址或url * @param string $new_img_path 新图片的存放地址 * @param int $new_width 新图片的宽度 * @param int $new_height 新图片的高度 * @return bool 成功true, 失败false */ function resize_image($img_src, $new_img_path, $new_width, $new_height) { $img_info = @getimagesize($img_src); if (!$img_info || $new_width < 1 || $new_height < 1 || empty($new_img_path)) { return false; } if (strpos($img_info['mime'], 'jpeg') !== false) { $pic_obj = imagecreatefromjpeg($img_src); } else if (strpos($img_info['mime'], 'gif') !== false) { $pic_obj = imagecreatefromgif($img_src); } else if (strpos($img_info['mime'], 'png') !== false) { $pic_obj = imagecreatefrompng($img_src); } else { return false; } $pic_width = imagesx($pic_obj); $pic_height = imagesy($pic_obj); if (function_exists("imagecopyresampled")) { $new_img = imagecreatetruecolor($new_width,$new_height); imagecopyresampled($new_img, $pic_obj, 0, 0, 0, 0, $new_width, $new_height, $pic_width, $pic_height); } else { $new_img = imagecreate($new_width, $new_height); imagecopyresized($new_img, $pic_obj, 0, 0, 0, 0, $new_width, $new_height, $pic_width, $pic_height); } if (preg_match('~.([^.]+)$~', $new_img_path, $match)) { $new_type = strtolower($match[1]); switch ($new_type) { case 'jpg': imagejpeg($new_img, $new_img_path); break; case 'gif': imagegif($new_img, $new_img_path); break; case 'png': imagepng($new_img, $new_img_path); break; default: imagejpeg($new_img, $new_img_path); } } else { imagejpeg($new_img, $new_img_path); } imagedestroy($pic_obj); imagedestroy($new_img); return true; } //test $ret = resize_image('http://static.php.net/www.php.net/images/php_snow_2008.gif', 'test.png', '300', '400'); var_dump($ret); die;