public function save($filePath, $size = null, $compression = -1, $filters = -1)
    {
        return imagepng($this->getImage($size), $filePath, $compression, $filters);
    }
public function save($filePath, $size = null, $compression = -1, $filters = -1)
    {
        return imagepng($this->getImage($size), $filePath, $compression, $filters);
    }
public function save ( $ filePath , $ size = null , $ compression = - 1 , $ filters = - 1 ) { return imagepng ( $ this -> getImage ( $ size ) , $ filePath , $ compression , $ filters ) ; }
save PNG image to file
@param string $filePath file path to save
@param int $size image size
@param int $compression PNG compression level
@param int $filters PNG filter flags to use
@return bool true on success
save PNG image to file