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sumitchatterjee13-Luminance…/luminance_stack_processor.py
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2025-09-20 23:40:01 +10:00

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Python

"""
Luminance Stack Processor - Professional ComfyUI Custom Nodes
Implements HDR processing using the Debevec Algorithm for multiple exposure fusion
Author: Sumit Chatterjee
Version: 1.0.0
Semantic Versioning: MAJOR.MINOR.PATCH
"""
import numpy as np
import torch
import cv2
from typing import Tuple, List
import logging
# Set up logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)
def tensor_to_cv2(tensor: torch.Tensor) -> np.ndarray:
"""Convert ComfyUI tensor to OpenCV format"""
# ComfyUI tensors are typically [B, H, W, C] in 0-1 range
if len(tensor.shape) == 4:
tensor = tensor.squeeze(0) # Remove batch dimension
# Convert to numpy and scale to 0-255
image = tensor.cpu().numpy()
if image.dtype == np.float32 or image.dtype == np.float64:
image = np.clip(image * 255.0, 0, 255).astype(np.uint8)
return image
def cv2_to_tensor(image: np.ndarray) -> torch.Tensor:
"""Convert OpenCV image to ComfyUI tensor format"""
# Ensure image is float32 in 0-1 range
if image.dtype == np.uint8:
image = image.astype(np.float32) / 255.0
elif image.dtype == np.uint16:
image = image.astype(np.float32) / 65535.0
elif image.dtype == np.float32:
image = np.clip(image, 0.0, 1.0)
# Add batch dimension and convert to tensor
tensor = torch.from_numpy(image).unsqueeze(0)
return tensor
class DebevecHDRProcessor:
"""Core HDR processing using Debevec Algorithm"""
def __init__(self):
self.calibrator = cv2.createCalibrateDebevec()
self.merge_debevec = cv2.createMergeDebevec()
def process_hdr(self, images: List[np.ndarray], exposure_times: List[float]) -> np.ndarray:
"""
Process multiple exposure images using Debevec algorithm
Args:
images: List of images (OpenCV format)
exposure_times: List of exposure times in seconds
Returns:
HDR merged image as 16-bit
"""
try:
# Ensure images are in uint8 format for calibration
processed_images = []
for img in images:
if img.dtype != np.uint8:
if img.dtype == np.float32:
img = np.clip(img * 255.0, 0, 255).astype(np.uint8)
else:
img = img.astype(np.uint8)
processed_images.append(img)
# Convert exposure times to numpy array
times = np.array(exposure_times, dtype=np.float32)
logger.info(f"Processing {len(processed_images)} images with exposure times: {times}")
# Estimate camera response function
response = self.calibrator.process(processed_images, times)
# Merge images into HDR
hdr = self.merge_debevec.process(processed_images, times, response)
# Convert HDR to 16-bit for better dynamic range preservation
# Apply tone mapping to fit into 16-bit range
hdr_normalized = cv2.normalize(hdr, None, 0, 65535, cv2.NORM_MINMAX)
hdr_16bit = hdr_normalized.astype(np.uint16)
logger.info(f"HDR processing completed. Output shape: {hdr_16bit.shape}")
return hdr_16bit
except Exception as e:
logger.error(f"HDR processing error: {str(e)}")
# Fallback: return the middle exposure image
if images:
middle_idx = len(images) // 2
fallback = images[middle_idx]
if fallback.dtype != np.uint16:
fallback = (fallback.astype(np.float32) * 257).astype(np.uint16)
return fallback
raise e
class LuminanceStackProcessor3Stops:
"""
Professional ComfyUI Custom Node for 3-stop HDR processing
Processes EV+2, EV+0, EV-2 exposures using Debevec Algorithm
"""
@classmethod
def INPUT_TYPES(cls):
return {
"required": {
"ev_plus_2": ("IMAGE",),
"ev_0": ("IMAGE",),
"ev_minus_2": ("IMAGE",),
},
"optional": {
"exposure_step": ("FLOAT", {
"default": 2.0,
"min": 0.5,
"max": 5.0,
"step": 0.1,
"display": "number"
}),
}
}
RETURN_TYPES = ("IMAGE",)
RETURN_NAMES = ("hdr_image",)
FUNCTION = "process_3_stop_hdr"
CATEGORY = "image/luminance"
def __init__(self):
self.processor = DebevecHDRProcessor()
def process_3_stop_hdr(self, ev_plus_2, ev_0, ev_minus_2, exposure_step=2.0):
"""
Process 3-stop HDR merge
Args:
ev_plus_2: Overexposed image (+2 EV)
ev_0: Normal exposure image (0 EV)
ev_minus_2: Underexposed image (-2 EV)
exposure_step: EV step size
Returns:
Tuple containing merged HDR image
"""
try:
# Convert tensors to OpenCV format
img_plus_2 = tensor_to_cv2(ev_plus_2)
img_0 = tensor_to_cv2(ev_0)
img_minus_2 = tensor_to_cv2(ev_minus_2)
# Calculate exposure times based on EV values
# EV difference formula: time = base_time * 2^(-EV_difference)
base_time = 1.0 / 60.0 # 1/60s as base exposure
time_plus_2 = base_time * (2.0 ** (-exposure_step)) # Shorter time (overexposed)
time_0 = base_time # Normal exposure
time_minus_2 = base_time * (2.0 ** exposure_step) # Longer time (underexposed)
images = [img_plus_2, img_0, img_minus_2]
times = [time_plus_2, time_0, time_minus_2]
logger.info(f"3-Stop HDR: Processing with times {times}")
# Process HDR
hdr_result = self.processor.process_hdr(images, times)
# Convert back to tensor
output_tensor = cv2_to_tensor(hdr_result)
return (output_tensor,)
except Exception as e:
logger.error(f"3-Stop HDR processing failed: {str(e)}")
# Return middle exposure as fallback
return (ev_0,)
class LuminanceStackProcessor5Stops:
"""
Professional ComfyUI Custom Node for 5-stop HDR processing
Processes EV+4, EV+2, EV+0, EV-2, EV-4 exposures using Debevec Algorithm
"""
@classmethod
def INPUT_TYPES(cls):
return {
"required": {
"ev_plus_4": ("IMAGE",),
"ev_plus_2": ("IMAGE",),
"ev_0": ("IMAGE",),
"ev_minus_2": ("IMAGE",),
"ev_minus_4": ("IMAGE",),
},
"optional": {
"exposure_step": ("FLOAT", {
"default": 2.0,
"min": 0.5,
"max": 5.0,
"step": 0.1,
"display": "number"
}),
}
}
RETURN_TYPES = ("IMAGE",)
RETURN_NAMES = ("hdr_image",)
FUNCTION = "process_5_stop_hdr"
CATEGORY = "image/luminance"
def __init__(self):
self.processor = DebevecHDRProcessor()
def process_5_stop_hdr(self, ev_plus_4, ev_plus_2, ev_0, ev_minus_2, ev_minus_4, exposure_step=2.0):
"""
Process 5-stop HDR merge
Args:
ev_plus_4: Most overexposed image (+4 EV)
ev_plus_2: Overexposed image (+2 EV)
ev_0: Normal exposure image (0 EV)
ev_minus_2: Underexposed image (-2 EV)
ev_minus_4: Most underexposed image (-4 EV)
exposure_step: EV step size
Returns:
Tuple containing merged HDR image
"""
try:
# Convert tensors to OpenCV format
img_plus_4 = tensor_to_cv2(ev_plus_4)
img_plus_2 = tensor_to_cv2(ev_plus_2)
img_0 = tensor_to_cv2(ev_0)
img_minus_2 = tensor_to_cv2(ev_minus_2)
img_minus_4 = tensor_to_cv2(ev_minus_4)
# Calculate exposure times based on EV values
base_time = 1.0 / 60.0 # 1/60s as base exposure
time_plus_4 = base_time * (2.0 ** (-2 * exposure_step))
time_plus_2 = base_time * (2.0 ** (-exposure_step))
time_0 = base_time
time_minus_2 = base_time * (2.0 ** exposure_step)
time_minus_4 = base_time * (2.0 ** (2 * exposure_step))
images = [img_plus_4, img_plus_2, img_0, img_minus_2, img_minus_4]
times = [time_plus_4, time_plus_2, time_0, time_minus_2, time_minus_4]
logger.info(f"5-Stop HDR: Processing with times {times}")
# Process HDR
hdr_result = self.processor.process_hdr(images, times)
# Convert back to tensor
output_tensor = cv2_to_tensor(hdr_result)
return (output_tensor,)
except Exception as e:
logger.error(f"5-Stop HDR processing failed: {str(e)}")
# Return middle exposure as fallback
return (ev_0,)
# Node class mappings for ComfyUI
NODE_CLASS_MAPPINGS = {
"LuminanceStackProcessor3Stops": LuminanceStackProcessor3Stops,
"LuminanceStackProcessor5Stops": LuminanceStackProcessor5Stops,
}
# Display names for nodes in ComfyUI interface
NODE_DISPLAY_NAME_MAPPINGS = {
"LuminanceStackProcessor3Stops": "Luminance Stack Processor (3 Stops)",
"LuminanceStackProcessor5Stops": "Luminance Stack Processor (5 Stops)",
}