ELI5: Explain Like I'm 5

Frequency separation

Frequency separation is like sorting things by size. Just like how we put big toys in one basket and small toys in another, we can sort pictures by their details.

When we take a picture, we capture different levels of details, some are small like a freckle on the nose or a fine hair, and some are bigger like the shape of the face or the color of the eyes. Frequency separation helps in separating these details into different layers, so we can work on them separately.

Imagine you have a cake with two layers, one layer has cream and the other one has chocolate. You can take them apart and work on them individually, either adding more cream or making the chocolate layer thicker. Similarly, with frequency separation, we can take the details layer by layer and work on them without affecting the other layers.

For example, with portrait photos, we can fix skin blemishes and wrinkles in the details layer without changing the colors and overall look of the skin in the bigger layer. It's like coloring inside the lines, but with pictures.

So, frequency separation helps us improve the quality of a picture by enabling us to work on specific details without affecting the rest of the photo.