Flux Image-to-Image Tutorial

Learn to use Flux model for image-to-image generation.

Image-to-Image Concept

Image-to-image generates new image based on existing image, preserving structure or style.

Installation

Required Models

ComfyUI/models/unet/
flux1-dev.safetensors    # Flux Dev

ComfyUI/models/vae/
flux_vae.safetensors     # Flux VAE

Basic Workflow

┌─────────────┐    ┌─────────────┐    ┌─────────────┐
│ LoadImage   │ →  │ VAEEncode  │ →  │ KSampler   │
│             │    │             │    │ (latent)   │
└─────────────┘    └─────────────┘    └─────────────┘
                                              │
┌─────────────┐    ┌─────────────┐    ┌──────┴──────┐
│ LoadCheckp  │ →  │ CLIPTextEn  │    │ VAEDecode  │
│ oint        │    │ code        │    │             │
└─────────────┘    └─────────────┘    └─────────────┘

Key Parameters

Denoise Strength

Value	Effect
0.1-0.3	Slight change, preserve original
0.4-0.6	Moderate change
0.7-0.9	Major change
1.0	Complete regeneration

Recommended Settings

Use Case	Denoise	Steps
Style transfer	0.4-0.6	20-30
Detail adjustment	0.2-0.4	20-30
Creative redraw	0.6-0.8	30-50

Applications

Style Transfer

Transform photo to art style:

Input: Portrait photo
Prompt: oil painting style, portrait, classical art
Denoise: 0.5-0.7

Color Adjustment

Adjust image tone and atmosphere:

Input: Ordinary photo
Prompt: warm golden hour lighting, sunset colors, cinematic
Denoise: 0.3-0.5

Scene Redraw

Change elements in scene:

Input: Indoor scene
Prompt: transform to outdoor garden, flowers and trees
Denoise: 0.6-0.8

Prompt Tips

Structure Preservation

Use "in the style of", "like":

a cat in the style of Studio Ghibli animation
a portrait like a vintage photograph

Element Replacement

Describe elements to change:

Original: a person with short hair
Prompt: the same person with long hair, flowing
Denoise: 0.5

Advanced

With ControlNet

┌─────────────┐    ┌─────────────┐
│ LoadImage   │ →  │ ControlNet │
│ (reference)│    │ Preprocessor│
└─────────────┘    └──────┬──────┘
                          ↓
┌─────────────┐    ┌─────────────┐
│ KSampler    │ ←  │ ApplyContro│
│             │    │ lNet       │
└─────────────┘    └─────────────┘

Troubleshooting

Q: Original image deformed

A: Lower denoise to 0.3-0.5, or use ControlNet for structure.

Q: Style not obvious

A: Increase denoise, use clearer style description.

Q: Generation time too long

A: Use Schnell version, or reduce steps.

Next Steps

• Flux ControlNet - Using ControlNet
• Inpainting - Local repair tutorial