Level set

Level set is like playing a game where you have to find out which area is higher or lower in a picture. The picture is divided into tiny squares and each square is given a color. The color can be red, green, blue or anything else.

So, when you have to find out which area is higher, you choose a color and imagine that color is like a wall. Then, you start walking inside the picture and wherever you cross that imaginary wall of your chosen color, you mark it as being "above" your chosen color or "below" your chosen color wall.

This is exactly what the level set does! It helps you find out which parts of a picture are higher or lower by using this imaginary wall of a chosen color. It looks at each tiny square, and tells you whether it is above or below that chosen color wall.

This is super useful when you want to find, for example, the outline of an object in the picture or calculate the amount of fluid in a tank, or even when you want to track the movement of a car in a video.

The level set helps you do this by dividing the whole picture into tiny squares, and by coloring them in such a way that you know which parts are higher or lower than your chosen wall. So cool, right?