Перестал работать код

function get_captcha(){
    
    header("Content-type: image/png");
    
    $imagec = imagecreate(175,35);
    $white = imagecolorallocate($image,255,255,255);
    $latin = array("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
    
    $col[0] = imagecolorallocate($imagec,255,0,0);
    $col[1] = imagecolorallocate($imagec,0,255,0);
    $col[2] = imagecolorallocate($imagec,0,0,255);
    $col[3] = imagecolorallocate($imagec,255,0,255);
    $col[4] = imagecolorallocate($imagec,255,255,122);
    $col[5] = imagecolorallocate($imagec,255,255,255);
    $i = rand(0,4);
    $ii = rand(0,4);
    $iii = rand(0,4);
    $a = rand(1,100);
    $b = rand(1,100);
    $c = rand(1,100);
    imageline($imagec,$a,$b,$c,$d,$col[$i]);
    imageline($imagec,$d,$c,$b,$a,$col[$ii]);
    $font_file = "fonts/Arial.ttf";
    $i_1 = rand(0,25);
    $i_2 = rand(0,4);
    $i_3 = rand(3,16);
    $i_4 = rand(8,9);
    $i_5 = rand(1,25);
    $i_6 = rand(1,7);
    $string = $latin[$i_1] . $i_2 . $latin[$i_3] . $i_4 . $latin[$i_5] . $i_6;
    imagettftext($imagec,14,0,55,25,$col[$iii],$font_file,$string);
    imagepng($imagec);
    imagedestroy($imagec);
    $str_captcha = $string;
    unset($string);
    setcookie("captcha",$str_captcha);
}