Why is Content-Type: image/jpeg header not working? [duplicate]

问题

This question already has answers here:

Image can not be displayed because it contains error in php gd (3 answers)

Closed 5 years ago.

I'm using GD library to resize image. Why is not header('Content-Type: image/jpeg'); working?

It gave me an error as you can see in pic below:

Here are my GD details:

.

<?php  
header("Content-type: image/jpeg");
if(isset($_GET['image'])){ 
    $image = $_GET['image'];
    list($image_width, $image_height)= getimagesize($image);
    $new_size = ($image_width+$image_height)/($image_width*($image_height/45));
    $new_width = $image_width * $new_size;
    $new_height = $image_height * $new_size;

    $new_image = imagecreatetruecolor($new_width, $new_height);
    $old_image = imagecreatefromjpeg($image);

    imagecopyresized($new_image, $old_image, 0, 0, 0, 0, $new_width, $new_height, $image_width, $image_height);
    imagejpeg($new_image);
}
?>

回答1:

It would always better to use the existing scripts/libraries instead of reinventing the wheel... try using timthumb or similar... that would save a lot of time and error free...

http://www.phpguy.in/simple-way-to-generate-thumbnails-in-php/

来源：https://stackoverflow.com/questions/23410195/why-is-content-type-image-jpeg-header-not-working