GD library create image with dynamic text on it

I want to place text generated dynamically from a sql select, on an image created with GD library. I'm using this to create the image and place some text on it, but I want to place the variable $users with the sql select data into the image:

$query = "SELECT id, name FROM users WHERE .... ORDER BY id DESC";
while ($line = mysql_fetch_assoc($query)) {

  $users .=  "<img src='https://www.example.com/" . $line['id'] . "/photo'/>&nbsp;" . $line['name'] . "<br />";
}



function  create_image(){
    $im = @imagecreate(550, 600)or die("Cannot Initialize new GD image stream");
    $background_color = imagecolorallocate($im, 255, 255, 0);  // yellow
    $red = imagecolorallocate($im, 255, 0, 0);      // red

    imagestring($im, 1, 5,  10, $users);
    imagestring($im, 2, 5,  50, "Text 2", $red);

    imagepng($im,"image.png");
    imagedestroy($im);
}

create_image();
print "<img src=image.png?".date("U").">";

The text in the $user variable not appear, how can I do this?

Thanks

Here is an example how to draw text on png image:

$img = imagecreatefrompng($image_path); //$image_path -> on which text to be drawn
        @imagealphablending($img, true);
        @imagesavealpha($img, true);
$textColor = imagecolorallocate($img, 100, 100, 98);
$font = '../fonts/Arial.ttf';

imagettftext($img, 18, 0, 140, 285,$textColor,$font, $name); // $name -> dynamic text to be drawn on image
$path = "path where you want to save created image";

$image = imagejpeg($img, $path);
imagedestroy($img);

done..