Resize image before uploading PHP - php

Question

I have no idea how to resize image in PHP, my code is:
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).
$dir = where the pics will be placed.
$ext = the type of the image (png, gif or jpg).
foreach loop runs two times because you can upload two pics.
This script is working good, I just need to do resize and I dont have an idea how to do it..

Answer 1

Here is the code I'm using to resize images.
In my case I give to the function the original file name and then the thumbnail file name.
You can adapt it for your case very easily.
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(!$success)
return 4;
}
return 0;
}
return 1;
}
The return codes are just here to differentiate between different types of errors.
By looking back at that code, I don't like the "magic number" trick. I'm gonna have to change that (by exceptions for example).
if (!empty($_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.
// 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);

Answer 2

Keep in mind that the picture you are dealing with is already uploaded on the server. You actualy want to resize picture before storing it in "safe place".
$_FILES["pic$index"]["tmp_name"] is probably /tmp/somepicturesname