Hello,

I would like to remove a few sizes of thumbnails, but I would like to do it in child theme function.php.

In woocommerce forum i found this:

add_action('init', 'remove_plugin_image_sizes');
function remove_plugin_image_sizes() {
    # remove_image_size('thumbnail'); // Wordpress (used by the media librairy to display thumbs)
    remove_image_size('wide'); // Wordpress
    remove_image_size('wide_small'); // Wordpress
    remove_image_size('regular'); // Wordpress
    remove_image_size('regular_small'); // Woocommerce

and this is exactly what I need, only for the Salient theme. 

Thank You

Best

Piotr

Thank you. However, your solution concerns the main template files. 

I want to overwrite it using Child Theme.