PHP獲取遠程驗證碼到本地的PHP函數(shù)代碼

    PHP獲取驗證碼圖片到本地，支持png、gif、jpg三種格式的驗證碼。在實現(xiàn)時，PHP判斷圖片格式是使用的php內(nèi)置的exif_imagetype函數(shù)，確實比較方便，學習PHP的不妨可參考下本代碼：
    view sourceprint?01
    02header("Content-type:image/png");
    03set_time_limit(0);//設置超時時間
    04$url = $_GET['url'];
    05$url = "";
    06if(empty($url)){
    07 echo "沒有圖片";
    08 die;
    09}
    10$imginfo = GetImageSize ( $url );
    11$type = exif_imagetype($url);
    12$imgw = $imginfo [0];
    13$imgh = $imginfo [1];
    14$bg = imagecreatetruecolor($imgw,$imgh);
    15if($type==IMAGETYPE_GIF){
    16 $image = imagecreatefromgif($url);
    17}elseif($type==IMAGETYPE_JPEG){
    18 $image = imagecreatefromjpeg($url);
    19}elseif($type==IMAGETYPE_PNG){
    20 $image = imagecreatefrompng($url);
    21}
    22imagecolorallocate($image,255,255,255);
    23imagecopy($bg,$image,0,0, 0,0,$imgw,$imgh);
    24imagedestroy($image);
    25ImagePng($bg);
    26?>