Except adding a format string isn't possible when using something like Core Image.How do we get Dynamic Media and Core components to respect transparency on images? If the source images has an alpha channel it stands to reason that the resulting variations would retain that. 

There is a solution: `alt="${properties.alt || true}"`Will render the authored value or `alt`https://github.com/adobe/aem-core-wcm-components/issues/1268#issuecomment-1126000022