Laravel 5 image resize

I use Laravel 5 and have a form to upload a image. When saving the file I have in my controller methods to get the image and put it in a directory:

if ($request->hasFile('picture')) {
    $destinationPath = 'uploads';
    $filename = $image->getClientOriginalName();
    $extension = $image->getClientOriginalExtension(); // add
    $picture = sha1($filename . time()) . '.' . $extension; //add
    $offer->image = $picture;
    $image->move($destinationPath, $picture);
}
$offer->save();

Before I save the file I would like to resize the file with a max. width of 800px. Is there a image resize or compression function in Laravel available? What would be the best idea to do this?