<?php
$absolute_path = __FILE__;
$path_to_file = explode( 'wp-content', $absolute_path );
$path_to_wp = $path_to_file[0];
require_once $path_to_wp.'/wp-load.php';
$do_blur = FALSE;
if(isset($_GET['src']) && !empty($_GET['src']))
{
	$image_id = letsblog_get_image_id($_GET['src']);
	if(!empty($image_id))
	{
		$do_blur = TRUE;
	}
}
$blurFactor = 5;
if(isset($_GET['blur_factor']) && is_numeric($_GET['blur_factor']))
{
	$blurFactor = $_GET['blur_factor'];
}
?>
<?php
function blur($gdImageResource, $blurFactor = 3)
{
  // blurFactor has to be an integer
  $blurFactor = round($blurFactor);
  
  $originalWidth = imagesx($gdImageResource);
  $originalHeight = imagesy($gdImageResource);

  $smallestWidth = ceil($originalWidth * pow(0.5, $blurFactor));
  $smallestHeight = ceil($originalHeight * pow(0.5, $blurFactor));

  // for the first run, the previous image is the original input
  $prevImage = $gdImageResource;
  $prevWidth = $originalWidth;
  $prevHeight = $originalHeight;

  // scale way down and gradually scale back up, blurring all the way
  for($i = 0; $i < $blurFactor; $i += 1)
  {    
    // determine dimensions of next image
    $nextWidth = $smallestWidth * pow(2, $i);
    $nextHeight = $smallestHeight * pow(2, $i);

    // resize previous image to next size
    $nextImage = imagecreatetruecolor($nextWidth, $nextHeight);
    imagecopyresized($nextImage, $prevImage, 0, 0, 0, 0, 
      $nextWidth, $nextHeight, $prevWidth, $prevHeight);

    // apply blur filter
    imagefilter($nextImage, IMG_FILTER_GAUSSIAN_BLUR);

    // now the new image becomes the previous image for the next step
    $prevImage = $nextImage;
    $prevWidth = $nextWidth;
      $prevHeight = $nextHeight;
  }

  // scale back to original size and blur one more time
  imagecopyresized($gdImageResource, $nextImage, 
    0, 0, 0, 0, $originalWidth, $originalHeight, $nextWidth, $nextHeight);
  imagefilter($gdImageResource, IMG_FILTER_GAUSSIAN_BLUR);

  // clean up
  imagedestroy($prevImage);

  // return result
  return $gdImageResource;
}
if($do_blur)
{
	header('Content-Type: image/jpeg');
	$image = imagecreatefromjpeg($_GET['src']);
	$new_image = blur($image,$blurFactor);
	imagejpeg($new_image);
	imagedestroy($new_image);
}
?>