Watermark an image

<?php 
// Create the canvas
$canvas = imagecreate( 200, 100 ); 

// Set the colours to use
$black = imagecolorallocate( $canvas, 0, 0, 0 ); 
$white = imagecolorallocate( $canvas, 255, 255, 255 );

// Create a rectangle 200 x 100 and fill it white 
imagefilledrectangle( $canvas, 0, 0, 200, 100, $white ); 

// Set the path to the font to use
$font = "../fonts/verdana.ttf"; 

// Set the text to use
$text = "Sunflower"; 

// Set the font size
$size = "30"; 

// Set the angle to rotate the font
// In this case the font was not rotated - It must need saving to a tempory image and rotating 
$degrees = "30"; 

// Set the image to watermark
$photo= "../original_images/sunflower.jpg";

// Find teh size of a bounding box for the text
// If php has not been setup with the correct ttf support this will not work
$box = imagettfbbox( $size, 0, $font, $text );
 
// Find the value to use for the position in x - placing central on the image
$x = (200 - ($box[2] - $box[0])) / 2;
 
// Setup the position for the y
$y = (100 - ($box[1] - $box[7])) / 2; 
$y -= $box[7]; 

// Create the box with the text
imageTTFText( $canvas, $size, 0, $x, $y, $black, $font, $text ); 

// Change the white to transparent
imagecolortransparent ( $canvas, $white );
 
// Rotate the text - didn't work
imagerotate( $canvas, $degrees, 0);
 
// Save the tempory image
imagepng( $canvas, "temp.png" );
 
// Clear the image from the memory
ImageDestroy( $canvas );
 
// Start a new image
$watermark = imagecreatefrompng('temp.png');
   
// Setup the image width and height
$watermark_width = imagesx( $watermark );   
$watermark_height = imagesy( $watermark );   
$image = imagecreatetruecolor( $watermark_width, $watermark_height );   
$image = imagecreatefromjpeg( $photo ); 

// Get the size of the photo to be watermarked  
$size = getimagesize( $photo );
   
// Calculate the position of the watermark
$dest_x = $size[0] - $watermark_width - 100;   
$dest_y = $size[1] - $watermark_height - 200;
   
// Put the watermark onto the photo
imagecopymerge($image, $watermark, $dest_x, $dest_y, 0, 0, $watermark_width, $watermark_height, 50);

// Save the watermarked photo   
imagejpeg( $image, 'watermark_GD.jpg' );
  
// Clear the images from the memory
imagedestroy( $image );   
imagedestroy( $watermark ); 
  
// Delete the tempory image
unlink( 'temp.png'); 
?>