Fixes "Cannot handle this data type: (1, 1, 1024), |u1" error in PreviewImage node:
- Maintain (H,W,C) tensor format instead of transposing to (C,H,W)
- Add explicit float32 data type conversion for PyTorch tensors
- Implement comprehensive error handling with fallback values
- Fix OpenCV guided filter data type compatibility issues
Ensures GrabCut nodes output tensors in ComfyUI's expected format:
(batch, height, width, channels) for images and (batch, height, width) for masks.
