how to insert a verified logo and digital signature in the uploaded document

Code:
if(isset($_FILES['image_file']))

{

    $max_size = 800; //max image size in Pixels

    $destination_folder = 'D:/Websites';

    $watermark_png_file = 'watermark.png'; //watermark png file

    

    $image_name = $_FILES['image_file']['name']; //file name

    $image_size = $_FILES['image_file']['size']; //file size

    $image_temp = $_FILES['image_file']['tmp_name']; //file temp

    $image_type = $_FILES['image_file']['type']; //file type



    switch(strtolower($image_type)){ //determine uploaded image type 

            //Create new image from file

            case 'image/png': 

                $image_resource =  imagecreatefrompng($image_temp);

                break;

            case 'image/gif':

                $image_resource =  imagecreatefromgif($image_temp);

                break;          

            case 'image/jpeg': case 'image/pjpeg':

                $image_resource = imagecreatefromjpeg($image_temp);

                break;

            default:

                $image_resource = false;

        }

    

    if($image_resource){

        //Copy and resize part of an image with resampling

        list($img_width, $img_height) = getimagesize($image_temp);

        

        //Construct a proportional size of new image

        $image_scale        = min($max_size / $img_width, $max_size / $img_height); 

        $new_image_width    = ceil($image_scale * $img_width);

        $new_image_height   = ceil($image_scale * $img_height);

        $new_canvas         = imagecreatetruecolor($new_image_width , $new_image_height);

        $text_color = imagecolorallocate($new_canvas, 233, 14, 91);

        imagestring($new_canvas, 1, 5, 5,  'A Simple Text String', $text_color);



        if(imagecopyresampled($new_canvas, $image_resource , 0, 0,0, 0, $new_image_width, $new_image_height, $img_width, $img_height))

        {

            

            if(!is_dir($destination_folder)){ 

                mkdir($destination_folder);//create dir if it doesn't exist

            }

            

            //center watermark

            $watermark_left = ($new_image_width/2)-(2/2); //watermark left            

            $watermark_bottom = ($new_image_height/2)-(2/2); //watermark bottom



            $watermark = imagecreatefrompng($watermark_png_file); //watermark image

            imagecopy($new_canvas, $watermark, $watermark_left, $watermark_bottom, 0, 0, 160, 128); //merge image

            

            //output image direcly on the browser.

            header('Content-Type: image/jpeg');

            

            

            imagejpeg($new_canvas, NULL , 90);

            

            //Or Save image to the folder

            //imagejpeg($new_canvas, $destination_folder.'/'.$image_name , 90);

            

            //free up memory

            imagedestroy($new_canvas); 

            imagedestroy($image_resource);

            die();

        }

    }

}