Can't use variables as image source

[DuendeInexistente]

Title says it all. It limits the plugin's usability in templates something fierce.

[CookiePLMonster]

I was able to use variables for the image source, but not for the alt text. In other words, neither of those produce the correct alt text:

            {%- assign image_url = item.image | relative_url -%}
            {% imagesize image_url:img alt=item.title %}

            {%- assign image_url = item.image | relative_url -%}
            {% imagesize image_url:img alt={{ item.title }} %}