Invert

Step: Stretch

Turns every pixel value around: black becomes white, white becomes black. On an RGB image every color channel is inverted on its own, so colors turn into their complements.

Parameters

This module has no parameters.

How it works

Each value v becomes 1 − v. Values outside 0…1, which can occur mid-pipeline, are mirrored the same way and are not clipped.

When to use it

• To look at faint structures as dark on light, which some people find easier to judge.
• As a step inside a technique that needs a negative, for example some star-reduction workflows.