ControlNet - Canny Edge

Learn to use Canny edge ControlNet.

What is Canny ControlNet

Canny edge detection extracts edges from input image, providing structure guidance for generation.

Installation

Download ControlNet Model

ComfyUI/models/controlnet/
  control_v11p_sd15_canny.pth

Download Preprocessor

ComfyUI usually includes preprocessors in:

ComfyUI/custom_nodes/comfyui_controlnet_aux/

Workflow

[LoadImage] → [CannyEdgePreprocessor] → [ControlNet] → [Apply ControlNet]
                                    ↑
[CLIPTextEncode(positive)] → [KSampler] ← [CLIPTextEncode(negative)]

Parameters

Canny Preprocessor

Parameter	Description	Recommended
Low Threshold	Lower edge detection	100-150
High Threshold	Upper edge detection	200-250

Lower values detect more edges (potential noise). Higher values detect only strong edges.

ControlNet Settings

Parameter	Description	Recommended
Strength	Control intensity	0.5-0.8
Start	Begin control at step	0.0
End	End control at step	1.0

Use Cases

Architecture

# Prompt
modern building exterior, glass facade, clean design, professional photography

# Input
Floor plan or line drawing

Product Design

# Prompt
sleek smartphone design, white, minimal, product photography

# Input
Product sketch or outline

Character Line Art

# Prompt
beautiful woman, detailed face, portrait

# Input
Line art drawing

Tips

1. Threshold adjustment: Start with 100/200, adjust based on results
2. Edge quality: Use clean, clear input images
3. Strength balance: Too high can flatten details

Common Issues

Issue	Solution
Too many edges	Increase threshold
Too few edges	Decrease threshold
Style too rigid	Lower strength to 0.3-0.5

Next Steps

• ControlNet Depth - Depth control
• ControlNet OpenPose - Pose control
• Multi-ControlNet - Combine multiple