How to Upload and Compress Image in PHP

<?php

/*$input_image="sample.jpg";

$output_image="output.jpg";

$img=imagecreatefromjpeg($input_image);

imagejpeg($img,$output_image,10);*/

if(isset($_POST['submit'])){

$info=getimagesize($_FILES['image']['tmp_name']);

if(isset($info['mime'])){

if($info['mime']=="image/jpeg"){

$img=imagecreatefromjpeg($_FILES['image']['tmp_name']);

}elseif($info['mime']=="image/png"){

$img=imagecreatefrompng($_FILES['image']['tmp_name']);

}else{

echo "Only select jpg or png image";

}

if(isset($img)){

$output_image=time().'.jpg';

imagejpeg($img,$output_image,40);

echo "Processing done";

}

}else{

echo "Only select jpg or png image";

}

}

?>

<form method="post" enctype="multipart/form-data">

<input type="file" name="image" required/>

<input type="submit" name="submit"/>

</form>