Nonlinear filter

Okay, imagine you have a box that takes in a bunch of different colored balls. Some balls are really big and some are really tiny. A linear filter would only let through the smaller balls, but a nonlinear filter would let through the bigger balls as well. It's like a different way of sorting the balls, so that even the bigger ones can fit through the filter. This can be useful when we want to look at all the balls together, not just the small ones. The same idea can be applied to other things too, like pictures or sounds, where we want to include all the details even if they are not the same size.