Image resizing does not work

Hi,

I created an article and added an image (ce_image) to that article. The actual picture is 590x323.
In the article image element I set the picture size to 100x100 and the resize mode to any possible option. The outcome is always the same: The generated html contains the original picture size and not the size I have set in the element.

Code:

---

<div class="ce_image block">
  <div class="image_container">
    [img]tl_files/path_to_image...[/img]
  </div>
</div>

---

Since I can't believe that such a fundamental function is still buggy, I assume that I am missing something here. Maybe a global setting or something so obvious that I overlooked it?

Any insight is appreciated.

I was right when I said that I was missing something obvious. What I was missing was the GDlib extension.
Sadly the system requirements are not noted at the beginning the Installation chapter of the user manual but under "Configuring the live server" which I thought was a chapter reserved for live server specific issues like security.