We actually don't, WebP can do this, but it's by no means common yet. This is actually a reasonable use of PNG still, it's optimizing the contents for the loss

We actually don't, WebP can do this, but it's by no means common yet. This is actually a reasonable use of PNG still, it's optimizing the contents for the lossless algorithm. You might be able to take the difference/error and put it in another image and layer them to make it give back the detail.