This is a pretty cool function. Sometimes the default Medium and Large sizes when inserting an image into a post just isn’t enough range. Maybe you have a special size you use in posts but don’t want to change your Medium and Large file sizes just for that? Well this snippet will allow you to add another image size to the WordPress drop down men…

Custom Media Size Dropdown

// Set the new image sizes
if(function_exists( 'add_image_size')){
  add_image_size('blog-large', 900, 700, false);
}

// Tell the media panel to add the new size to the dropbown
function custom_image_sizes($sizes) {
        $addsizes = array(
                "blog-large" => __("X-Large")
                );
        $newsizes = array_merge($sizes, $addsizes);
        return $newsizes;
}
add_filter('image_size_names_choose', 'custom_image_sizes');