Using ImagicMagick with Wordpress (Specifically doing a color image overlay)

gistfile1.php

  function make_blue_image($data){
		
		if(!empty($data)) {
		
			$upload_dir   = wp_upload_dir();
		
			if(!empty($data['sizes']) && array_key_exists('blue', $data['sizes'])) {
				$filepath = $upload_dir['basedir'] . DIRECTORY_SEPARATOR . dirname($data['file']) . DIRECTORY_SEPARATOR . $data['sizes']['blue']['file'];
			}
			
      //Image to lay on top
			$bluepath = TEMPLATEPATH . "/blue.png";
      //Path to ImagicMagick could be different (this is homebrew)
			$command = "/usr/local/bin/composite " . $bluepath ." ". $filepath ." -compose Multiply -gravity center " . $filepath . " 2>&1";
		}

		// pass forward attachment metadata
		return $data;
	}
  
    add_filter('wp_generate_attachment_metadata', 'make_blue_image');