public function getFormattedImage($format, $arg1 = null, $arg2 = null) {
if($this->ID && $this->Filename && Director::fileExists($this->Filename)) {
$size = getimagesize(Director::baseFolder() . '/' . $this->getField('Filename'));
$preserveOriginal = false;
switch(strtolower($format)){
case 'croppedimage':
$preserveOriginal = ($arg1 == $size[0] && $arg2 == $size[1]);
break;
case 'croppedfromtopimage':
$preserveOriginal = ($arg1 == $size[0] && $arg2 == $size[1]);
break;
}

if($preserveOriginal){
return $this;
} else {
return parent::getFormattedImage($format, $arg1, $arg2);
}
}
}

/**
    * Generate a resized copy of this image with the given width & height. Cropped from top-center
    * Use in templates with $CroppedFromTopImage.
    */
   function generateCroppedFromTopImage($gd, $width, $height) {
      if(is_numeric($gd) || !$gd){
         USER_ERROR("Image::generateFormattedImage - generateCroppedFromTopImage is being called by legacy code or gd is not set.",E_USER_WARNING);
      }else{
         
         if($gd->getWidth / $gd->getHeight >= $width/$height){
            $gd = $gd->resizeByHeight($height);
            $left = ($gd->getWidth - $width)/2; //center cropped image.
            // if you want to cut from top left or right make $left = 0 or $gd->getWidth - $width respectively
         }else{
            $gd = $gd->resizeByWidth($width);   
            $left = 0;
         }
         return $gd->crop(0, $left, $width, $height);
      }
   }