#php: scale image by percent ratio

                                                $ratioH = $h / $objImg->getImageHeight();
                        $ratioW = $w / $objImg->getImageWidth();
                        $minRatio = min($ratioH, $ratioW);

                        $newH = $objImg->getImageHeight() * $minRatio;
                        $newW = $objImg->getImageWidth() * $minRatio;