In re my last rant about using CSS layering to get rid of JPEG artifacts in images where text has been added, for completeness I present to you a similar version using the canvas HTML tag. If you are using a browser that supports the tag, you should see something that approximates the previous set of images:
This time, the overlay in the top left isn’t even an image — it’s a drawn element. Setting aside my schoolchild-level of graphical skills, you can at least get the idea.