GD2簡單裁圖寫法

$big_width=550;
$big_height=500;
$small_width=143;
$small_height=104;

$destDir = "upload_image/news";

//檔案命名
$Name = date("YmdHis") . "_" . substr(md5(uniqid(rand())),0,5) . "." . $Ext;
//複製暫存檔
copy($_FILES['Photo3']['tmp_name'][$i] , $destDir . "/" . $Name );

//預覽圖
$src = $destDir . "/" . $Name;
$dest = $destDir . "/thum/" . "thum_" . $Name;
$destW = $small_width;
$destH = $small_height;
$nb3=$Name;//存圖片名稱
imagesResizeSmall($src,$dest,$destW,$destH);

function imagesResizeSmall($src,$dest,$destW,$destH) {
if (file_exists($src) && isset($dest)) {
//取得檔案資訊
$srcSize = getimagesize($src);
$srcExtension = $srcSize[2];
$srcRatio = $srcSize[0] / $srcSize[1];
//依長寬比判斷長寬像素
$destH = $destW / $srcRatio;
}

//建立影像 建立小圖的框
if($destH>=104){
$destImage = imagecreatetruecolor($destW, 104);
}else{
$destImage = imagecreatetruecolor($destW, $destH);
}
//根據檔案格式讀取圖檔
switch ($srcExtension) {
case 1: $srcImage = imagecreatefromgif($src); break;
case 2: $srcImage = imagecreatefromjpeg($src); break;
case 3: $srcImage = imagecreatefrompng($src); break;
}

//取樣縮圖 取大圖縮放後 放在小圖的框裡
imagecopyresampled($destImage, $srcImage, 0, 0, 0, 0,$destW,$destH,imagesx($srcImage), imagesy($srcImage));

//輸出圖檔
switch ($srcExtension) {
case 1: imagegif($destImage,$dest); break;
case 2: imagejpeg($destImage,$dest,100); break;
case 3: imagepng($destImage,$dest); break;

//釋放資源
imagedestroy($destImage);
}
}