This plugin allow you set image for category.
At the front-end, you can use class for element "c4d-category-image"
Or try php code with function c4d_category_image() and return is image's url.
This plugin is used in C4D Vision - Responsive WooCommerce Theme
You can view here http://coffee4dev.com/responsive-woocommerce-theme-c4d-vision/
安装:
Upload c4d-category-image to the /wp-content/plugins/ directory
Activate the plugin through the 'Plugins' menu in WordPress