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php上傳圖片生成縮略圖（GD庫）

編輯：PHP綜合

首先來一段簡單的php上傳圖片生成縮略圖的詳細代碼，分享給大家供大家參考，具體內容如下

<?php
function createThumbnail($imageDirectory, $imageName, $thumbDirectory, $thumbWidth, $quality){
$details = getimagesize("$imageDirectory/$imageName") or die('Please only upload images.');
$type = preg_replace('@^.+(?<=/)(.+)$@', '$1', $details['mime']);
eval('$srcImg = imagecreatefrom'.$type.'("$imageDirectory/$imageName");');
$thumbHeight = $details[1] * ($thumbWidth / $details[0]);
$thumbImg = imagecreatetruecolor($thumbWidth, $thumbHeight);
imagecopyresampled($thumbImg, $srcImg, 0, 0, 0, 0, $thumbWidth, $thumbHeight,
$details[0], $details[1]);
eval('image'.$type.'($thumbImg, "$thumbDirectory/$imageName"'.
(($type=='jpeg')?', $quality':'').');');
imagedestroy($srcImg);
imagedestroy($thumbImg);
}
foreach ($_FILES["pictures"]["error"] as $key => $error) {
if ($error == UPLOAD_ERR_OK) {
$tmp_name = $_FILES["pictures"]["tmp_name"][$key];
$name = $_FILES["pictures"]["name"][$key];
move_uploaded_file($tmp_name, "data/$name");
createThumbnail("/location/of/main/image", $name, "/location/to/store/thumb", 120, 80);
//120 = thumb width :: 80 = thumb quality (1-100)
}
}
?>

接下來再為大家推薦一個實例php使用GD庫上傳圖片以及創建縮略圖，直接看代碼：

GD庫是PHP進行圖象操作一個很強大的庫。

先在php.ini裡增加一行引用：extension=php_gd2.dll

重啟apache，做一個測試頁var_dump(gd_info());輸出數據表明GD庫引用成功。

圖片上傳頁面 upload.html

<html>
<head>
<meta http-equiv='Content-Type' content='text/html; charset=utf-8'>
<title>圖片上傳</title>
</head>
<body>
<h1>文件上傳(只允許上傳jpg類型圖片)</h1>
<form enctype="multipart/form-data" action="upload_img.php" method="post">
 <input name="upfile" type="file"><br><br>
 <input type="submit" value="提交">
</form>
</body>
</html>

處理頁面upload_img.php

<?php
 //上傳圖片保存地址
 $uploadfile = "upfiles/".$_FILES['upfile']['name'];
 //縮略圖保存地址
 $smallfile = "upfiles/small_".$_FILES['upfile']['name'];


 if($_FILES['upfile']['type'] != "image/jpeg")
 {
  echo '文件類型錯誤';
 }
 else
 {
  move_uploaded_file($_FILES['upfile']['tmp_name'],$uploadfile); //上傳文件

  $dstW=200;//縮略圖寬
  $dstH=200;//縮略圖高

  $src_image=ImageCreateFromJPEG($uploadfile);
  $srcW=ImageSX($src_image); //獲得圖片寬
  $srcH=ImageSY($src_image); //獲得圖片高

  $dst_image=ImageCreateTrueColor($dstW,$dstH);
  ImageCopyResized($dst_image,$src_image,0,0,0,0,$dstW,$dstH,$srcW,$srcH);
  ImageJpeg($dst_image,$smallfile);

  echo '文件上傳成功<br>';
  echo "<img src='$smallfile' />";
 }
?>

希望對大家學習php程序設計有所幫助，謝謝大家的支持。

PHP綜合