[css] Darkening an image with CSS (In any shape)

Webkit only solution

Quick solution, relies on the -webkit-mask-image property. -webkit-mask-image sets a mask image for an element.

There are a few gotchas with this method:

  • Obviously, only works in Webkit browsers
  • Requires an additional wrapper to apply the :after psuedo-element (IMG tags can't have :before/:after pseudo elements, grr)
  • Because there's an additional wrapper, I'm not sure how to use the attr(…) CSS function to get the IMG tag URL, so it's hard-coded into the CSS separately.

If you can look past those issues, this might be a possible solution. SVG filters will be even more flexible, and Canvas solutions will be even more flexible and have a wider range of support (SVG doesn't have Android 2.x support).