Image quality

Hello in 3.5.1 there’s

/**
195	         * Sets Image Compression quality on a 1-100% scale.
196	         *
197	         * @since 3.5.0
198	         * @access public
199	         *
200	         * @param int $quality Compression Quality. Range: [1,100]
201	         * @return boolean
202	         */
203	        public function set_quality( $quality ) {
204	                $this->quality = apply_filters( 'wp_editor_set_quality', $quality );
205
206	                return ( (bool) $this->quality );
207	        }

http://core.trac.wordpress.org/browser/tags/3.5.1/wp-includes/class-wp-image-editor.php#L194

How can i set the images to be 80? what do I have to add? what is the code and where?

Thanks!