Intelligent Image Expansion: Mastering Flux Fill with Wan2.1 Workflow
1. Workflow Overview

This "Wan2.1 Preprocessor" workflow utilizes Flux Flill model to intelligently outpaint input images into square compositions. It combines Differential Diffusion with Flux Guidance for seamless edge transitions.
2. Core Models
Model File | Function | Installation |
---|---|---|
flux1-fill-dev.safetensors | Flux outpainting specialist | Manual placement required |
t5xxl_fp8_e4m3fn.safetensors | Flux text encoder | Must be in |
3. Critical Nodes
DifferentialDiffusion (Node 39):
Dynamically adjusts edge generation intensity
▶ Requires Flux-series modelsImage Comparer (rgthree):
Interactive before/after comparison UI
▶ Install viaComfyUI-rgthree
extension
4. Workflow Logic
Data Preprocessing Group:
Automatically processes all images in input directory
Calculates padding dimensions through math nodes
Outpainting Group:
Generates padding mask via AI analysis
Performs latent space diffusion (20 steps)
Outputs 4K-ready square images
5. Key Parameters
Input:
Source image directory (modifiable)
Seed: 764442076935121
Output:
Saved to local path with metadata
6. Pro Tips
⚠️ Requirements:
Minimum 8GB VRAM for 1024x1024 generation
Correct model folder structure
💡 Recommended:Use
--medvram
flag for GPUs <12GBAdjust KSampler scheduler per hardware