PHP thumbnail code to achieve full pane equal proportion reduction

/**
* Scaled down thumbnails
* edit bbs.it-home.org
*/
    function thumbs($FileName,$SaveTo,$SetW,$SetH){
        $IMGInfo= getimagesize($FileName);
        if(!$IMGInfo) return false;
        if($IMGInfo[mime]== "image/pjpeg" || $IMGInfo[mime]=="image/jpeg"){
            $ThisPhoto= imagecreatefromjpeg($FileName);
        }elseif($IMGInfo[mime]== "image/x-png" || $IMGInfo[mime]== "image/png"){
            $ThisPhoto= imagecreatefrompng($FileName);
        }elseif($IMGInfo[mime]== "image/gif"){
            $ThisPhoto=imagecreatefromgif($FileName);
        }
        $width=$IMGInfo[0];
        $height=$IMGInfo[1];
        $scalc = max($width/$SetW,$height/$SetH);
        $nw = intval($width/$scalc);
        $nh = intval($height/$scalc);
        echo "缩略大小：w$nw,h$nh ";
        if($SetW-$nw == 1){$nw = $SetW;}
        if($SetH-$nh == 1){$nh = $SetH;}
        echo "+修正1像素： w$nw,h$nh";
        //补宽
        if($SetW-$nw > 0){
            $nh = $nh +(($nh/$nw) * ($SetW-$nw));
            echo "*需补宽".($SetW-$nw).",陪补高".(($nh/$nw) * ($SetW-$nw))."  ";
            $nw = $SetW;
        }
        //补高
        if($SetH-$nh > 0){
            $nw = $nw + (($nw/$nh) * ($SetH-$nh));
            echo "*需补高".($SetH-$nh).",陪补宽". (($nw/$nh) * ($SetH-$nh)) ."";
            $nh = $SetH;
        }

        $nw = intval($nw);
        $nh = intval($nh);
        echo "+修正大小：w$nw,h$nh";
        $px = ($SetW - $nw)/2;
        $py = ($SetH - $nh)/2;
        echo "窗口大小：w$SetW,h$SetH ";
        echo "+偏移修正：x$px,y$py ";
        $NewPhoto=imagecreatetruecolor($SetW,$SetH);
        imagecopyresized($NewPhoto,$ThisPhoto,$px,$py,0,0,$nw,$nh,$width,$height);
        ImageJpeg ($NewPhoto,$SaveTo);
        return true;
    }
    thumbs('a.jpg','newa.jpg',150,70);
?>

2，css代码部

3，html页面中的图片地址