Opencart 2.3.0.2 : Category image on product pages

Question

I kinda know this should be a fairly simple thing to do, but in my opencart 2.3.0.2 webshop, I want to display the category image on product pages.

But i cant find how to retrieve the image.... At this moment i have this piece of code :

  <div class="catthumb">
    <?php if ($thumb) { ?>
  <div class="category-bg" style="    
     background: url('<?php echo $thumb; ?>') no-repeat center center; 
     -webkit-background-size: cover;
     -moz-background-size: cover;
     -o-background-size: cover;
     background-size: cover;
     filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src='.<?php echo $thumb; ?>', sizingMethod='scale');
     -ms-filter: "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='<?php echo $thumb; ?>', sizingMethod='scale')";">
  </div>
    <?php } ?>

The following code doesn't do the trick.. Ofcourse i've changed the variable along with the code.

        if ($category_info) {
            if ($category_info['image']) {
            $this->data['thumbcat'] = "../image/".($category_info['image']);
            } else {
            $this->data['thumbcat'] = '';
            }
        }

But this displays the poduct thumb, instead of the category thumb, the product belongs to.

So the question is how to get the category image there?

Thanks in advance!