A powerful ComfyUI extension for handling image resolutions. It provides smart, model-aware resolution presets and robust resizing tools, designed for "engineering-grade" automation.

🌟 Features

Dynamic Dropdowns: The size dropdown smartly filters to show only relevant presets for your selected model (e.g., selecting "Flux" hides "Qwen" sizes).
Model-Aware Resolution: Automatically snaps resolutions to specific multiples required by different architectures:
- Flux / Z-Image / Illustrious: Multiples of 32
- Qwen-Image: Multiples of 28
Smart Custom Logic: Seamlessly switch between presets and custom sizes without fighting the UI.
Robust Resizing: Includes an advanced AutoSize node for images/masks with multiple modes:
- Center Crop / Edge Crop
- Scale to Fit (Letterboxing)
- Stretch to Fill

📦 Provided Nodes

1. Auto Size Latent

Category: latent/AutoSize

Generates an empty latent tensor for starting a workflow.

Inputs:
- model: Select standard (Flux, Qwen, etc.) or specific architectures.
- size: Choose a preset (e.g., Flux - 16:9) or Full Custom.
- custom_longer_size: Target pixel size for the longer side. Set to 0 to use the size dropdown.
- custom_ratio: Target aspect ratio (used only when custom_longer_size > 0).
- batch_size: Number of latents to generate.
Outputs: latent, width, height, size (string).

2. Auto Size (Image/Mask)

Category: image/AutoSize

Resizes an existing image and/or mask to target dimensions. Perfect for image-to-image workflows.

Inputs: Same as above, plus:
- crop_method: Strategy if aspect ratios don't match (Crop vs Fit vs Stretch).
- scale_method: Interpolation (Lanczos, Bicubic, Nearest, etc.).
- image (Optional): Input image to resize.
- mask (Optional): Input mask to resize.
Outputs: Resized image, resized mask, and dimension info.

🛠️ Installation

Navigate to your ComfyUI custom nodes directory:
```
cd ComfyUI/custom_nodes
```

Clone this repository:

git clone https://github.com/jluo-github/comfyui-auto-size.git

Restart ComfyUI.
- Note: If the dynamic dropdowns don't appear immediately, try reloading the browser page.

⚙️ How It Works (The Logic)

The nodes use a Priority System to determine the final resolution:

Custom Override (custom_longer_size > 0):
- If you set custom_longer_size to any value greater than 0, the node ignores the Size dropdown.
- It calculates the resolution using custom_longer_size + custom_ratio.
- It strictly aligns the result to the selected model's required multiple (e.g., rounding to nearest 32px or 28px).
Preset Mode (custom_longer_size = 0):
- If custom_longer_size is 0 (default), the node uses the resolution from the Size dropdown (e.g., Flux - 16:9).

💻 Development

The project is structured for maintainability and pure Python logic where possible.

nodes/: ComfyUI node definitions.
utils/: Core logic (presets, math, resizing) decoupled from ComfyUI.
js/: Frontend extensions for dynamic UI behavior.

Running Tests

To verify the math and resize logic:

python -m unittest discover -s tests

License

MIT License

Made with ❤️ for the ComfyUI community