Be able to exclude different image types

The most common problem for me here is that i've had several sites with an background image within a div, instead of the usual img tag. This causes problems with ALT texts, since w3.org regards this as bad SEO, if it is within a div. 

The problem could be solved by filtering different errors. Such as allowing the ALT from img tags but not showing the errors from the background images. As of now, i can exclude entire pages, or exclude the all the missing alt texts.
But since i need this, because i'm still using the feature, to show some of the changes to the ALT, it would be nice to be able to filter it out somehow. Excluding errors in divs maybe?