图片上传有效，缩略图歪斜？

Posted 2023-03-29

【中文标题】图片上传有效，缩略图歪斜？

【英文标题】：Image upload works, thumbnail is skewed?

【发布时间】：2015-09-22 23:14:02

【问题描述】：

上传到我的服务器时，常规图像上传正常，但对于某些图像，在创建缩略图时，法师会旋转，我不知道为什么或我的代码发生了什么？

请注意，我使用的是旧语法，我知道它很丑，但我很懒，但它可以工作。

<? session_start(); ?>
<? include('header.inc.php'); ?>
<?
    if(isset($_POST['upload_Submit'])) 
     $_SESSION['success'] = 0;
     $upPath = "/home/dolphina/public_html/images/";
     $fileName = uniqid(time().date(mdY));
     $_SESSION['upload_Error'] = 0;
     $error_Log = "<ul>";
      if ($_FILES['upload_Image']['size'] > 10000000) 
       $error_Log .= "<li>image is greater than 10 megabyte</li>";
        $_SESSION['upload_Error'] = 1;
      
      if (($_FILES['upload_Image']['type'] == "image/gif") || ($_FILES['upload_Image']['type'] == "image/pjpeg") || ($_FILES['upload_Image']['type'] == "image/jpeg") || ($_FILES['upload_Image']['type'] == "image/png")) 
       if($_FILES['upload_Image']['type'] == "image/gif") 
        $fileExt = ".gif";
        
       if($_FILES['upload_Image']['type'] == "image/pjpeg") 
         $fileExt = ".jpg";
       
       if($_FILES['upload_Image']['type'] == "image/jpeg") 
        $fileExt = ".jpeg";
       
       if($_FILES['upload_Image']['type'] == "image/png") 
         $fileExt = ".png";
       
       else 
      $error_Log .= "<li>invalid image type</li>";
      $_SESSION['upload_Error'] = 1;
    
    if(!$_POST['upload_Caption']) 
      $error_Log .= "<li>no caption entered</li>";
      $_SESSION['upload_Error'] = 1;
    
    if(!$_POST['upload_Password']) 
      $error_Log .= "<li>no password entered</li>";
      $_SESSION['upload_Error'] = 1;
    
    if($_POST['upload_Password'] != "3") 
      $error_Log .= "<li>wrong password</li>";
      $_SESSION['upload_Error'] = 1;
    
   $error_Log .= "</ul>";
    if($_SESSION['upload_Error'] == 1) 
      echo $error_Log;
      $_SESSION['upload_Error'] = 0;
     else 
      //COPIES TEMP FILE TO PATH
    copy($_FILES['upload_Image']['tmp_name'], $upPath."pics/".$fileName.$fileExt);
    $first=ImageCreateFromJPEG($upPath."pics/".$fileName.$fileExt);
  echo "GOT HERE";
//CREATES AND COPIES THUMBNAIL TO PATH
function make_thumb($src, $dest, $desired_width) 

  /* read the source image */
  $source_image = imagecreatefromjpeg($src);
  $width = imagesx($source_image);
  $height = imagesy($source_image);

  /* find the "desired height" of this thumbnail, relative to the desired width  */
  $desired_height = floor($height * ($desired_width / $width));

  /* create a new, "virtual" image */
  $virtual_image = imagecreatetruecolor($desired_width, $desired_height);

  /* copy source image at a resized size */
  imagecopyresampled($virtual_image, $source_image, 0, 0, 0, 0, $desired_width, $desired_height, $width, $height);

  /* create the physical thumbnail image to its destination */
  imagejpeg($virtual_image, $dest);

make_thumb($upPath."pics/".$fileName.$fileExt, $upPath."thumb/thumbnail_".$fileName.$fileExt, 300);
//INSERT INTO DATABASE
      $upImage = "INSERT INTO `images` (`url`, `thumb`, `date`, `time`, `ip`, `caption`) VALUES ('images/pics/".$fileName.$fileExt."', 'images/thumb/thumbnail_".$fileName.$fileExt."', CURDATE(), CURTIME(), '".$_SERVER['REMOTE_ADDR']."', '".$_POST['upload_Caption']."')";
      $upFINAL = mysqli_query($mysql_conn, $upImage);
      $_SESSION['success'] = 1;
    
  
  if($_SESSION['success'] == 1)  echo("<div>SUCCESS</div>");
?>
<style>
ul  padding: 0; margin: 0; margin-left: 4px; 
</style>
<form method="POST" enctype="multipart/form-data" action="upload.php">
<div>File</div>
<div><input type="file" name="upload_Image" size="40"></div>
<div>Caption</div>
<div><input type="text" name="upload_Caption" size="40"></div>
<div><input type="password" name="upload_Password" size="40"></div>
<div><input type="submit" name="upload_Submit" value="Upload Image"></div>
</form>
</div>

【问题讨论】：

您能否添加一张不适合缩略图处理的图片示例？

看起来你也使用 imagecreatefromjpeg() 而不管输入格式，虽然这应该只是失败而不是输出无聊的图像。

【参考方案1】：

在 PHP 文档中，comment 112902 on imagecreatefromjpeg 的引用是这样说的：

imagecreatefromjpeg() 此函数不支持 EXIF 方向数据。使用 EXIF 旋转的图片，经过 imagecreatefromjpeg() 处理后会以原来的方向显示。

您的缩略图可能只是显示其原始方向。这是假设您的图像查看器实际上尊重该标志。

此外，如果输入不是 jpeg，您可能不应该使用 imagecreatefromjpeg()。