ComfyUI/custom_nodes/ComfyUI-KJNodes/utility/utility.py

import torch
import numpy as np
from PIL import Image
from typing import Union, List

# Utility functions from mtb nodes: https://github.com/melMass/comfy_mtb
def pil2tensor(image: Union[Image.Image, List[Image.Image]]) -> torch.Tensor:
    if isinstance(image, list):
        return torch.cat([pil2tensor(img) for img in image], dim=0)

    return torch.from_numpy(np.array(image).astype(np.float32) / 255.0).unsqueeze(0)


def np2tensor(img_np: Union[np.ndarray, List[np.ndarray]]) -> torch.Tensor:
    if isinstance(img_np, list):
        return torch.cat([np2tensor(img) for img in img_np], dim=0)

    return torch.from_numpy(img_np.astype(np.float32) / 255.0).unsqueeze(0)


def tensor2np(tensor: torch.Tensor):
    if len(tensor.shape) == 3:  # Single image
        return np.clip(255.0 * tensor.cpu().numpy(), 0, 255).astype(np.uint8)
    else:  # Batch of images
        return [np.clip(255.0 * t.cpu().numpy(), 0, 255).astype(np.uint8) for t in tensor]
    
def tensor2pil(image: torch.Tensor) -> List[Image.Image]:
    batch_count = image.size(0) if len(image.shape) > 3 else 1
    if batch_count > 1:
        out = []
        for i in range(batch_count):
            out.extend(tensor2pil(image[i]))
        return out

    return [
        Image.fromarray(
            np.clip(255.0 * image.cpu().numpy().squeeze(), 0, 255).astype(np.uint8)
        )
    ]