What are preprocessors?
Preprocessors are foundational tools that extract structural information from images. They convert images into conditioning signals like depth maps, lineart, pose skeletons, and surface normals. These outputs drive better control and consistency in ControlNet, image-to-image, and video workflows. Using preprocessors as separate workflows enables:- Faster iteration without full graph reruns
- Clear separation of preprocessing and generation
- Easier debugging and tuning
- More predictable image and video results
Depth estimation
Depth estimation converts a flat image into a depth map representing relative distance within a scene. This structural signal is foundational for controlled generation, spatially aware edits, and relighting workflows. This workflow emphasizes:- Clean, stable depth extraction
- Consistent normalization for downstream use
- Easy integration with ControlNet and image-edit pipelines
Depth Estimation Workflow
Run on Comfy Cloud
Lineart conversion
Lineart preprocessors distill an image down to its essential edges and contours, removing texture and color while preserving structure. This workflow is designed to:- Produce clean, high-contrast lineart
- Minimize broken or noisy edges
- Provide reliable structural guidance for stylization and redraw workflows
Lineart Conversion Workflow
Run on Comfy Cloud
Pose detection
Pose detection extracts body keypoints and skeletal structure from images, enabling precise control over human posture and movement. This workflow focuses on:- Clear, readable pose outputs
- Stable keypoint detection suitable for reuse across frames
- Compatibility with pose-based ControlNet and animation pipelines
Pose Detection Workflow
Run on Comfy Cloud
Normals extraction
Normals estimation converts a flat image into a surface normal map—a per-pixel direction field that describes how each part of a surface is oriented (typically encoded as RGB). This signal is useful for relighting, material-aware stylization, and highly structured edits. This workflow emphasizes:- Clean, stable normal extraction with minimal speckling
- Consistent orientation and normalization for reliable downstream use
- ControlNet-ready outputs for relighting, refinement, and structure-preserving edits
- Reuse across passes so you can iterate without re-running earlier steps
- Drive relight/shading changes while preserving geometry
- Add a stronger 3D-like structure to stylization and redraw pipelines
- Improve consistency across frames when paired with pose/depth for animation work
Normals Extraction Workflow
Run on Comfy Cloud
Getting started
1
Update ComfyUI
Update ComfyUI to the latest version or use Comfy Cloud
2
Load the workflow
Download the workflows linked above or find them in Templates on Comfy Cloud
3
Install dependencies
Follow the pop-up dialogs to download the required models and custom nodes
4
Run the workflow
Review inputs, adjust settings, and run the workflow
Related tutorials
- ControlNet - Use preprocessor outputs with ControlNet
- Depth ControlNet - Depth-guided image generation
- Pose ControlNet - Pose-guided image generation