This also problem for me, because what i want is to have different sub category images for different sub category according by the product on the sub category. Here is a quick how to have different images.
1. Depend on your method to insert images to the header, are you using tag or css ?
If you are using an tag, and you have an image for every subcategory, you can simply use the following code in header.tpl :
<img src="{$img_dir}header{$smarty.get.id_category}.jpg" />
Then you would put header.jpg, header13.jpg, header14.jpg and header15.jpg in the img directory of your theme's directory.
If you need only a few header images to be different and the rest will use the default image, you'll need to use the following code in header.tpl instead :
<img src="{$img_dir}header{if $smarty.get.id_category == 13 OR $smarty.get.id_category == 14 OR $smarty.get.id_category == 15}{$smarty.get.id_category}{/if}.jpg" />If you are using CSS to display your images, you'll need to add a class to container of the image using the following code :
{if $smarty.get.id_category} class="cat{$smarty.get.id_category}"{/if}Then you can use the following code in global.css to display the different images :
.cat13 { background: url(../img/header13.jpg); }
.cat14 { background: url(../img/header14.jpg); }
.cat15 { background: url(../img/header15.jpg); }