This filter detects edges in the active layer or selection and gives them a bright neon effect.

You will find in GIMP a Script-Fu also named Neon, which works in a different manner. The Script-Fu is an easy shortcut to construct logo-like letters outlined with a configurable neon-effect. See 第 16.18 节 “Neon” for details.

You can find this filter through Filters → Edge-Detect → Neon....