在上传 PHP 之前调整图像大小
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Resize image before uploading PHP
提问by Luis
I have no idea how to resize image in PHP, my code is:
我不知道如何在 PHP 中调整图像大小，我的代码是：
for ($index = 1; $index <= 2; $index++) {
if (!empty($_FILES["pic$index"]["name"])) {
$ext = substr($_FILES["pic$index"]["name"], strrpos($_FILES["pic$index"]["name"], '.') + 1);
$dir = "../gallery/$mkdir";
HERE I NEED THE RESIZE OF THE TMP FILE OF IMAGE
move_uploaded_file($_FILES["pic$index"]["tmp_name"] , "$dir/img-$index.$ext");
}
}
$mkdir = the name of the gallery's folder (there are many galleries).
$mkdir = 画廊文件夹的名称（有很多画廊）。
$dir = where the pics will be placed.
$dir = 放置图片的位置。
$ext = the type of the image (png, gif or jpg).
$ext = 图像的类型（png、gif 或 jpg）。
foreach loop runs two times because you can upload two pics.
foreach 循环运行两次，因为您可以上传两张图片。
This script is working good, I just need to do resize and I dont have an idea how to do it..
这个脚本运行良好，我只需要调整大小，我不知道该怎么做..
回答by Lo?c Février
Here is the code I'm using to resize images.
这是我用来调整图像大小的代码。
In my case I give to the function the original file name and then the thumbnail file name.
在我的例子中，我给函数提供了原始文件名，然后是缩略图文件名。
You can adapt it for your case very easily.
你可以很容易地根据你的情况调整它。
public static function GenerateThumbnail($im_filename,$th_filename,$max_width,$max_height,$quality = 0.75)
{
// The original image must exist
if(is_file($im_filename))
{
// Let's create the directory if needed
$th_path = dirname($th_filename);
if(!is_dir($th_path))
mkdir($th_path, 0777, true);
// If the thumb does not aleady exists
if(!is_file($th_filename))
{
// Get Image size info
list($width_orig, $height_orig, $image_type) = @getimagesize($im_filename);
if(!$width_orig)
return 2;
switch($image_type)
{
case 1: $src_im = @imagecreatefromgif($im_filename); break;
case 2: $src_im = @imagecreatefromjpeg($im_filename); break;
case 3: $src_im = @imagecreatefrompng($im_filename); break;
}
if(!$src_im)
return 3;
$aspect_ratio = (float) $height_orig / $width_orig;
$thumb_height = $max_height;
$thumb_width = round($thumb_height / $aspect_ratio);
if($thumb_width > $max_width)
{
$thumb_width = $max_width;
$thumb_height = round($thumb_width * $aspect_ratio);
}
$width = $thumb_width;
$height = $thumb_height;
$dst_img = @imagecreatetruecolor($width, $height);
if(!$dst_img)
return 4;
$success = @imagecopyresampled($dst_img,$src_im,0,0,0,0,$width,$height,$width_orig,$height_orig);
if(!$success)
return 4;
switch ($image_type)
{
case 1: $success = @imagegif($dst_img,$th_filename); break;
case 2: $success = @imagejpeg($dst_img,$th_filename,intval($quality*100)); break;
case 3: $success = @imagepng($dst_img,$th_filename,intval($quality*9)); break;
}
if(!$success)
return 4;
}
return 0;
}
return 1;
}
The return codes are just here to differentiate between different types of errors.
返回码只是为了区分不同类型的错误。
By looking back at that code, I don't like the "magic number" trick. I'm gonna have to change that (by exceptions for example).
回顾那段代码，我不喜欢“幻数”把戏。我将不得不改变它（例如例外）。
if (!empty($_FILES["pic$index"]["name"])) {
$ext = substr($_FILES["pic$index"]["name"], strrpos($_FILES["pic$index"]["name"], '.') + 1);
$dir = "../gallery/$mkdir";
// Move it
if(move_uploaded_file($_FILES["pic$index"]["tmp_name"] , "$dir/img-$index.$ext.tmp"))
{
// Resize it
GenerateThumbnail("$dir/img-$index.$ext.tmp","$dir/img-$index.$ext",600,800,0.80);
// Delete full size
unlink("$dir/img-$index.$ext.tmp");
}
}
Use move_uploaded_file to move it (recommanded) and then you can resize it and send it to it's final destination. You might not even need the ".tmp", you can use.
使用 move_uploaded_file 移动它（推荐），然后你可以调整它的大小并将它发送到它的最终目的地。你甚至可能不需要“.tmp”，你可以使用。
// Move it
if(move_uploaded_file($_FILES["pic$index"]["tmp_name"] , "$dir/img-$index.$ext"))
// Resize it
GenerateThumbnail("$dir/img-$index.$ext","$dir/img-$index.$ext",600,800);
回答by Aif
Keep in mind that the picture you are dealing with is alreadyuploaded on the server. You actualy want to resize picture before storing it in "safe place".
请记住，您正在处理的图片已经上传到服务器上。您实际上想在将图片存储在“安全位置”之前调整图片大小。
$_FILES["pic$index"]["tmp_name"]is probably /tmp/somepicturesname
$_FILES["pic$index"]["tmp_name"]可能是 /tmp/ somepicturesname
