PHP resize image, convert to jpg, and display in browser

Question

I have a form to upload a file:

<form method="POST" action="upload-image.php">
    <input type="file" name="file"><br>
    <input type="submit" value="Submit">
</form>

And a PHP code to resize the uploaded file (image), convert it to JPG, and display it in the browser.

<?php
function image_to_jpg($src_file){
    $file = $_FILES["file"]["name"];
    $ext = end(explode(".",$file));
    list($width_orig,$height_orig) = getimagesize($src_file);
    $width  = 128;
    $height = 128;
    ini_set("memory_limit","32M");
    if($ext == "jpg" || $ext == "jpeg"){
        $image = imagecreatefromjpeg($file);
    }
    if($ext == "gif"){
            $image = imagecreatefromgif($file); 
    }
    if($ext == "png"){
        $image = imagecreatefrompng($file);
    }
    $new_image = imagecreatetruecolor($width,$height);
    imagecopyresampled($new_image,$image,0,0,0,0,$width,$height,$width_orig,height_orig);
    $dest_file = "ok.jpg";
    header("Content-Type: image/jpeg");
    imagejpeg($new_image,$dest_file);
}
$src_file = $_FILES["file"]["tmp_name"];
image_to_jpg($src_file);
?>

It is not working. It displays a blank image. What is my error?

Note: Code adapted from the post accepted as answer at:

How do I resize and convert an uploaded image to a PNG using GD

Answer 1

Cause you use imagejpeg($new_image,$dest_file); your scaled image is written to ok.jpg. Don't use the second parameter to output to the browser directly.

header("Content-Type: image/jpeg");
imagejpeg($new_image);
imagedestroy($new_image);
exit;