Resize copied image on upload as thumbnail - php

Question

I am working on an uploader and slowly getting it working, I am uploading 3 images at once, and setting arrays for each one as keys, with an increment of ++1. I am wanting to resize the image before it gets copied to the thumbnail folder.
I have this code.
Everything works with it.
As you see, I started on getting the file info, but after that I am totally stuck on what to do after to resize the image proportionally with a maximum width of xpx and height to match it without looking distorted.
Any help would be really appreciated. Thank You.
EDIT --- I started working on it myself and wondering if this is the right approach to what i am doing.
<?php
if (isset($_POST['addpart'])) {
$image = $_FILES['images']['tmp_name'];
$name = $_POST['username'];
$i = 0;
foreach ($image as $key) {
$fileData = pathinfo(basename($_FILES["images"]["name"][$i]));
$fileName[] = $name . '_' . uniqid() . '.' . $fileData['extension'];
move_uploaded_file($key, "image/" . end($fileName));
copy("image/" . end($fileName), "image_thumbnail/" . end($fileName));
// START -- THE RESIZER THAT IS BEING WORKED ON
$source = "image_thumb/" . end($fileName);
$dest = "image_thumb/" . end($fileName);
$quality = 100;
$scale = 1 / 2;
$imsize = getimagesize($source);
$x = $scale * $imsize[0];
$y = $scale * $imsize[1];
$im = imagecreatefromjpeg($source);
$newim = imagecreatetruecolor($x, $y);
imagecopyresampled($newim, $im, 0, 0, 0, 0, $x, $y, $imsize[0], $imsize[1]);
imagejpeg($newim, $dest, $quality);
// END -- THE RESIZER THAT IS BEING WORKED ON
$i++;
}
echo 'Uploaded<br>';
echo 'Main Image - ' . $fileName[0] . '<br>';
echo 'Extra Image 1 - ' . $fileName[1] . '<br>';
echo 'Extra Image 2 - ' . $fileName[2] . '<br>';
echo '<hr>';
}
?>
thanks

Answer 1

Use GD library.
Create input image object using imagecreatefromstring() for example: imagecreatefromstring(file_get_contents($_FILES['images']['tmp_name'][$i]))
It's the simplest way.
Another option is to detect file type and use functions like imagecreatefromjpeg (), imagecreatefrompng(), etc.
Create output empty image using imagecreate()
Use imagecopyresampled() or imagecopyresized() to resize image and copy+paste it from input image to output image
Save output image using function like imagejpeg()
Clean memory using imagedestroy()

Answer 2

The built-in image manipulation commands of PHP makes your code difficult to understand and to maintain. I suggest you to use a library which wraps it into a more productive way.
If you use Intervention/image, for example, your code will look like this:
<?php
// target file to manipulate
$filename = $_FILES['images']['tmp_name'];
// create image instance
$img = Image::make($filename);
// resize to width, height
$img->resize(320, 240);
// save it!
$img->save('thumbs/'. uniqid() . '.' . pathinfo($filename, PATHINFO_EXTENSION));
Read the full documentation here: http://image.intervention.io/use/uploads