Scratch

<?PHP
//parser in spaces
$count = 1;
$string = str_replace("_"," ",$_GET['string']);
if(isset($_GET['bgimage']) && strstr($_GET['bgimage'], ".png")){ #thanks to LS97 for making most of the bgimage attribute!
    // create the background
    $img = imagecreatefrompng($_GET['bgimage']);
    
    //chooses the text color
        if(isset($_GET['textr']) | isset($_GET['textg']) | isset($_GET['textb'])){
        $red = (int)$_GET['textr'];
        $green = (int)$_GET['textg'];
        $blue = (int)$_GET['textb'];
        $text_colour = imagecolorallocate($img, $red, $blue, $green);
    }
    else{
        $text_colour = imagecolorallocate($img, 0, 0, 0);
    }
    
    // get the font
    $font = realpath('Trebuchet_MS.ttf');
    
    // print the string
    imagettftext($img, 13, 0, 5, 20, $text_colour, $font, $string);
    
    // tell browser about content type
    header( 'Content-type: image/png' );
    // create image
    imagepng( $img );
}
if(!isset($_GET['bgimage'])){
    // Set font size
    $font_size = 2;
    if(isset($_GET['font_size'])){
        $font_size = $_GET['font_size'];
    }
    $font = '/fonts/Trebuchet_MS.ttf';
    if(isset($_GET['font'])){
        $font = $_GET['font'];
    }
    // Create image width dependant on width of the string
    $width  = imagefontwidth($font_size)*strlen($string);
    if(isset($_GET['width'])){
        $width = $_GET['width'];
    }
    // Set height to that of the font
    $height = imagefontheight($font_size);
    if(isset($_GET['height'])){
        $height = $_GET['height'];
    }
    // Create the image pallette
        $img = imagecreate($width,$height);
        if(isset($_GET['bgr']) | isset($_GET['bgg']) | isset($_GET['bgb'])){
            $red = (int)$_GET['bgr'];
            $blue = (int)$_GET['bgg'];
            $green = (int)$_GET['bgb'];
            $bg    = imagecolorallocate($img, $red, $blue, $green);
        }
        else{
            $bg    = imagecolorallocate($img, 222, 223, 223);
        }
    // Font color
    if(isset($_GET['textr']) | isset($_GET['textg']) | isset($_GET['textb'])){
        $red = (int)$_GET['textr'];
        $green = (int)$_GET['textg'];
        $blue = (int)$_GET['textb'];
        $color = imagecolorallocate($img, $red, $blue, $green);
    }
    else{
        $color = imagecolorallocate($img, 0, 0, 0);
    }

    // Length of the string
    if(isset($_GET['limitstring'])){
        if(strlen($string) > $_GET['limitstring']){
            $string= substr($string, 0, $_GET['limitstring']);
        }
    }
    $len = strlen($string);
    // Y-coordinate of character, X changes, Y is static
    $ypos = 0;
    if(isset($_GET['ypos'])){
        $ypos = $_GET['ypos'];
    }
    // Loop through the string
    for($i=0;$i<$len;$i++){
        // Position of the character horizontally
        if(isset($_GET['xpos'])){
            $xpos = $i * imagefontwidth($font_size) + $_GET['xpos'];
        }
        else{
            $xpos = $i * imagefontwidth($font_size);
        }
        // Draw character
        imagechar($img, $font_size, $xpos, $ypos, $string, $color);
        // Remove character from string
        $string = substr($string, 1);   
    
    }
    // Return the image
    header("Content-Type: image/gif");
    imagegif($img);
}
// Remove image
imagedestroy($img);

?>