[Custom node] Mask Smoothing Node

Mask Fourier Smoothing — ComfyUI Custom Node

Smooth out jagged mask edges using Fourier Descriptor algorithm — a classic signal processing

technique applied to contour shapes.

What it does

This node takes a mask as input, extracts its contour, applies FFT-based low-pass filtering

in the frequency domain, and reconstructs a clean, smooth mask. No blur, no dilation — just

mathematically smooth edges.

How it works

The contour points are encoded as complex numbers (x + jy) and transformed via FFT. By

keeping only the low-frequency Fourier components and discarding the high-frequency ones

(which represent sharp corners and noise), the inverse FFT reconstructs a naturally smoothed

contour.

Parameters

- num_descriptors (default: 32, range: 4–512) — Controls how many frequency components are

kept. Lower = smoother. Higher = closer to original.

Use cases

- Cleaning up hand-painted masks from inpainting workflows

- Smoothing segmentation masks before feeding into ControlNet

- Removing jagged artifacts from any binary mask

Installation

custom_nodes/

└── ComfyUI_MaskSmoothing/