PHP Image Scaling Implementation method

  This article mainly introduces the PHP image scaling implementation method, the need for friends can refer to the following

PHP Basic Exercise-image scaling:       Code as follows: <?php    /**     * Image zoom.    /    function Imagezoom ($filename, $w, $h) {       /Arguments meaning * *        /* $filename: The source of the name * */        * $w: Want get the I Mage ' s width */       /* $h: You want get the Imgage ' s height */        $arr = GetImageSize ($filename);         $SRC _w = $arr [0];         $SRC _h = $arr [1];         $SRC _t = $arr [2];        /*1 = gif,2 = jpg,3 = png,4 = swf,5 = psd,6 = bmp,7 = TIFF (Intel byte order) = TIFF (Motorola byte order), 9 = jpc,10 = jp2,11 = jpx,12 = jb2,13 = SWC, = iff,15 = wbmp,16 = xbm*/        $SRC _m = $ Arr[' MIME '];           $SRC _img = Imagecreatefromjpeg ($filename);           if (($w/$src _w) > ($h/$src _h)) {            $bili = $h/$src _h;       &NB Sp else {            $bili = $w/$src _h;        }         $DST _w = $src _w * $bili;         $DST _h = $src _h * $bili;         $DST _img = Imagecreatetruecolor ($dst _w, $dst _h);           imagecopyresampled ($dst _img, $src _img, 0, 0, 0, 0, $dst _w, $dst _h, $src _w, $src _h);           header ("content-type:{$src _m}");           switch ($src _t) {            Case 1:     &NBSP ;           $imgout = "Imagegif";                 break;             Case 2:                 $imgout = "image JPEG ";         &nbsp       break;             Case 3:                 $imgout = "image PNG ";                 break;             default:                 echo "the type Was wrong! ";                 break;        }           $DST _filename = "S_". $filename;         $imgout ($dst _img, $dst _filename);           Imagedestroy ($dst _img);    }     $filename = ' gg.jpg ';     Imagezoom ($filename, 100, 200);       Core:<1> Note how scaling is achieved, although the resulting picture may be somewhat different from what is expected, but at least the scaling is guaranteed.   <2> type of control.