用php创建缩略图imagejpeg-获取错误“；无法打开流:权限被拒绝”；

我正在尝试使用此功能创建以前上传的图像的缩略图。

原始图像上传到mysite/used_ploads，缩略图应在mysite/uused_ploads_thb创建。

缩略图功能是在上传原稿后直接触发的。

我还更改了目录的权限，如下所示，但问题仍然存在。

chmod（"used_uploads_thb"，0777）；

目录如下：

mysite/used_ploads

mysite/used_ploads_thb

这就是整个剧本。最后一步是给出上述错误。

<?php
$src = substr($filePath, 1);
//$src example: used_uploads/252-558ec2e5dc45c-alfa-romeo-giulia - 2.jpg
chmod("used_uploads_thb", 0777);
$dest = '/used_uploads_thb';
$desired_width="100";
function make_thumb($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, $dest);
                  print_r(error_get_last());              
}
make_thumb($src, $dest, $desired_width);
?>

这是错误消息：

Array
(
[type] => 2
[message] => imagejpeg(/used_uploads_thb): failed to open stream:    Permission denied
[file] => /Applications/MAMP/htdocs/SiteCar/used_thumbnail.php
[line] => 26
)

我感谢你的帮助。

<?php
$src = $new_name = $filePath;
$new_name = preg_replace('/used_uploads'/(.*)$/', '$1', $new_name);
$src = $_SERVER['DOCUMENT_ROOT'] . $src;
$dest = 'used_uploads_thb'. $new_name;
$desired_width="100";

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,$dest);
    //print_r(error_get_last());
}
 make_thumb($src, $dest, $desired_width);
?>