PHP - imagettftext - Unicode characters

Question

Unicode characters shows a set of rectangles on the image. I tried to fix it in these way, but it does not work.

$text = mb_convert_encoding($text, 'HTML-ENTITIES',"UTF-8");
$text = html_entity_decode($text,ENT_NOQUOTES, "ISO-8859-1");
imagettftext($image, 10, 10, 50, 50, $black, $font,$text);