1. Fix tensor dimension mismatch error: - Flux apply_model expects different signature: (x, t, c_concat=None, c_crossattn=None, ...) - Try multiple parameter combinations to find correct signature - Add fallback strategies for different input formats 2. Add comprehensive hook triggering strategies: - Try apply_model with c_crossattn parameter - Fallback to minimal apply_model call - Access internal diffusion_model and double_blocks - Manually trigger computation in individual blocks 3. Enhanced error handling: - Multiple fallback levels for model execution - Detailed logging at each attempt - Try to trigger hooks even if full model execution fails This should resolve the 'Tensors must have same number of dimensions' error and provide multiple ways to trigger the registered hooks for attention capture.
ComfyUI-Concept-Diffusion
ComfyUI custom node implementation of ConceptAttention: Diffusion Transformers Learn Highly Interpretable Features.
This node allows you to generate high-quality saliency maps that precisely locate textual concepts within images using diffusion transformer attention layers.
Features
- ConceptAttention Node: Extract concept embeddings from diffusion transformer attention layers
- Saliency Map Generation: Generate precise saliency maps for textual concepts
- Zero-shot Segmentation: Perform zero-shot semantic segmentation using concept attention
- Multi-concept Support: Handle multiple concepts simultaneously
- Video Support: Works with video generation models (CogVideoX)
- Visualization Tools: Overlay attention maps on original images
- Flexible Thresholding: Multiple threshold methods for saliency maps
Installation
-
Clone this repository to your ComfyUI custom_nodes folder:
git clone https://github.com/Junst/ComfyUI-Concept-Diffusion.git cd ComfyUI-Concept-Diffusion -
Install dependencies:
pip install -r requirements.txt -
Restart ComfyUI
Nodes
ConceptAttentionNode
Main node for generating concept attention maps from diffusion models.
Inputs:
model: Diffusion model (MODEL)clip: CLIP text encoder (CLIP)image: Input image (IMAGE)concepts: Comma-separated list of concepts (STRING)num_inference_steps: Number of inference steps (INT)seed: Random seed (INT, optional)
Outputs:
concept_maps: Generated concept attention maps (CONCEPT_MAPS)visualized_image: Visualization of all concept maps (IMAGE)
ConceptSaliencyMapNode
Extract individual concept saliency maps and convert to masks.
Inputs:
concept_maps: Concept attention maps (CONCEPT_MAPS)concept_name: Name of concept to extract (STRING)threshold: Threshold for mask generation (FLOAT)
Outputs:
mask: Binary mask for the concept (MASK)saliency_image: Saliency map visualization (IMAGE)
ConceptSegmentationNode
Perform zero-shot semantic segmentation using concept attention.
Inputs:
concept_maps: Concept attention maps (CONCEPT_MAPS)image: Original image (IMAGE)concepts: List of concepts for segmentation (STRING)
Outputs:
segmentation_mask: Segmentation mask (MASK)segmented_image: Colored segmentation result (IMAGE)
ConceptAttentionVisualizerNode
Visualize concept attention maps overlaid on the original image.
Inputs:
concept_maps: Concept attention maps (CONCEPT_MAPS)image: Original image (IMAGE)overlay_alpha: Transparency of overlay (FLOAT)
Outputs:
visualized_image: Image with attention overlay (IMAGE)
Usage Example
- Load an image using
LoadImagenode - Load a diffusion model (Flux, SD3, etc.) using
CheckpointLoaderSimple - Connect the model, CLIP, and image to
ConceptAttentionNode - Specify concepts like "person, car, tree, sky, building"
- Use
ConceptSaliencyMapNodeto extract specific concept maps - Use
ConceptSegmentationNodefor zero-shot segmentation - Use
ConceptAttentionVisualizerNodefor visualization - Save results using
SaveImagenodes
Example Workflow
See example_workflow.json for a complete ComfyUI workflow example.
Testing
Run the test script to verify the nodes work correctly:
python test_nodes.py
Technical Details
This implementation is based on the ConceptAttention paper which shows that:
- Multi-modal diffusion transformers (DiTs) have rich representations
- Linear projections in the attention output space produce sharper saliency maps
- Concept embeddings can be extracted without additional training
- The method works for both image and video generation models
Supported Models
- Flux (Flux1-dev, Flux1-schnell)
- Stable Diffusion 3/3.5
- CogVideoX (for video)
- Other DiT-based diffusion models
Based on
ConceptAttention: Diffusion Transformers Learn Highly Interpretable Features
License
MIT License