zero order search, loading verifiers

This commit is contained in:
MaximClouser
2025-02-26 19:05:09 +00:00
parent b77feba398
commit df93865bf5
+513 -165
View File
@@ -1,224 +1,572 @@
import json
import logging
import os
import traceback
from typing import Dict, List, Optional, Tuple, Any
import ImageReward as reward
import torch
import torch.nn.functional as F
import comfy.samplers
from huggingface_hub import snapshot_download
from torchvision.transforms import ToPILImage
from torchvision.utils import make_grid
from transformers import CLIPProcessor, CLIPModel
import comfy.sample
import comfy.samplers
import comfy.sd
import comfy.utils
import folder_paths
import latent_preview
import json
from torchvision.utils import make_grid
from torchvision.transforms import ToPILImage
# from comfy.utils import ProgressBar
from transformers import CLIPProcessor, CLIPModel
import ImageReward as reward
from .qwen_verifier import QwenVLMVerifier
from .utils import generate_neighbors
logging.basicConfig(
level=logging.INFO,
format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
logger = logging.getLogger('inferencescale')
def common_ksampler(model, seed, steps, cfg, sampler_name, scheduler, positive, negative, latent, denoise=1.0, disable_noise=False, start_step=None, last_step=None, force_full_denoise=False):
def common_ksampler(model, seed, steps, cfg, sampler_name, scheduler, positive, negative, latent, denoise=1.0,
disable_noise=False, start_step=None, last_step=None, force_full_denoise=False,
override_noise=None):
latent_image = latent["samples"]
latent_image = comfy.sample.fix_empty_latent_channels(model, latent_image)
if disable_noise:
if override_noise is not None:
noise = override_noise.to(latent_image.device)
elif disable_noise:
noise = torch.zeros(latent_image.size(), dtype=latent_image.dtype, layout=latent_image.layout, device="cpu")
else:
batch_inds = latent["batch_index"] if "batch_index" in latent else None
batch_inds = latent.get("batch_index", None)
noise = comfy.sample.prepare_noise(latent_image, seed, batch_inds)
noise_mask = None
if "noise_mask" in latent:
noise_mask = latent["noise_mask"]
noise_mask = latent.get("noise_mask", None)
# callback = latent_preview.prepare_callback(model, steps)
# disable_pbar = not comfy.utils.PROGRESS_BAR_ENABLED
disable_pbar = True
callback = None
samples = comfy.sample.sample(
model=model,
noise=noise,
steps=steps,
cfg=cfg,
sampler_name=sampler_name,
scheduler=scheduler,
positive=positive,
negative=negative,
latent_image=latent_image,
denoise=denoise,
disable_noise=disable_noise,
start_step=start_step,
last_step=last_step,
force_full_denoise=force_full_denoise,
noise_mask=noise_mask,
callback=callback,
disable_pbar=disable_pbar,
seed=seed
)
callback = latent_preview.prepare_callback(model, steps)
disable_pbar = not comfy.utils.PROGRESS_BAR_ENABLED
samples = comfy.sample.sample(model, noise, steps, cfg, sampler_name, scheduler, positive, negative, latent_image,
denoise=denoise, disable_noise=disable_noise, start_step=start_step, last_step=last_step,
force_full_denoise=force_full_denoise, noise_mask=noise_mask, callback=callback, disable_pbar=disable_pbar, seed=seed)
out = latent.copy()
out["samples"] = samples
return (out, )
def compute_similarity(clip_model, clip_processor, text, image) -> float:
# Process inputs: 'text' is a string, and 'image' should be a PIL image
inputs = clip_processor(text=[text], images=image, return_tensors="pt", padding=True)
device = next(clip_model.parameters()).device
inputs = {k: v.to(device) for k, v in inputs.items()}
# Get text and image embeddings.
with torch.no_grad():
text_embeddings = clip_model.get_text_features(
input_ids=inputs['input_ids'],
attention_mask=inputs['attention_mask']
)
image_embeddings = clip_model.get_image_features(
pixel_values=inputs['pixel_values']
)
text_embeddings = F.normalize(text_embeddings, dim=-1)
image_embeddings = F.normalize(image_embeddings, dim=-1)
similarity = F.cosine_similarity(text_embeddings, image_embeddings)
# rounded_similarity = round(similarity.item(), 4)
rounded_similarity = similarity.item()
return rounded_similarity
def compute_combined_verifier_score(candidate_image, text_prompt, verifiers, weights):
def rank_candidates(results_by_verifier, num_candidates):
"""
verifiers: a dict with keys like 'clip' and 'image_reward' and values holding the corresponding model(s)/processor(s)
weights: a dict with the same keys, providing a float weight for each verifier
Returns a combined score and a dict of individual scores.
results_by_verifier: {
'clip': [score0, score1, ...],
'image_reward': [...],
'qwen_vlm_verifier': [...],
...
}
Convert each verifier's raw scores into ranks (best=rank 1), then compute
an average rank for each candidate, returning a list of dicts sorted by avg_rank.
"""
scores = {}
ranks_by_verifier = {}
for verifier_name, scores_list in results_by_verifier.items():
# Sort indices by descending score (best score = rank 1)
sorted_indices = sorted(range(len(scores_list)), key=lambda i: scores_list[i], reverse=True)
rank_array = [0] * len(scores_list)
for rank, idx in enumerate(sorted_indices):
rank_array[idx] = rank + 1 # best = rank 1
ranks_by_verifier[verifier_name] = rank_array
if 'clip' in verifiers and verifiers['clip'] is not None:
clip_model, clip_processor = verifiers['clip']
clip_score = compute_similarity(clip_model, clip_processor, text_prompt, candidate_image)
scores['clip'] = clip_score
if 'image_reward' in verifiers and verifiers['image_reward'] is not None:
image_reward_model = verifiers['image_reward']
image_reward_score = image_reward_model.score(text_prompt, candidate_image)
scores['image_reward'] = image_reward_score
combined_score = 0.0
for key, score in scores.items():
# TODO Implement algo from paper to combine scores
combined_score += weights.get(key, 1.0) * score
combined_score = round(combined_score, 4)
return combined_score, scores
n_verifiers = len(results_by_verifier)
final_results = []
for i in range(num_candidates):
sum_ranks = 0
image_scores = {}
for verifier_name, score_list in results_by_verifier.items():
image_scores[verifier_name] = score_list[i]
sum_ranks += ranks_by_verifier[verifier_name][i]
avg_rank = (sum_ranks / n_verifiers) if n_verifiers > 0 else 9999
final_results.append({"index": i, "avg_rank": avg_rank, "scores": image_scores})
# Sort ascending by avg_rank (lower is better)
final_results.sort(key=lambda x: x["avg_rank"])
return final_results
class MaximKSampler:
def score_candidates(candidate_tensors: List[torch.Tensor], text_prompt: str, verifier_names: Dict[str, Any]) -> List[Dict[str, float]]:
"""
Scores each candidate image using the provided verifier ensemble.
Args:
candidate_tensors: List of image tensors to score
text_prompt: Text prompt to compare against
verifier_names: Dictionary of verifier instances
Returns:
List of score dictionaries, one per candidate
"""
num_candidates = len(candidate_tensors)
raw_scores_list = [{} for _ in range(num_candidates)]
try:
if not candidate_tensors:
raise ValueError("No candidate tensors provided for scoring")
if not text_prompt:
logger.warning("Empty text prompt provided for scoring")
for verifier_name, verifier in verifier_names.items():
if verifier is None:
continue
logger.info(f"Scoring {num_candidates} candidates with {verifier_name}")
try:
with torch.no_grad():
for i, tensor_img in enumerate(candidate_tensors):
try:
pil_img = ToPILImage()(tensor_img.squeeze(0).permute(2, 0, 1))
if verifier_name == "clip":
score = verifier.score(text_prompt, pil_img)
elif verifier_name == "image_reward":
score = verifier.score(text_prompt, pil_img)
elif verifier_name == "qwen_vlm_verifier":
score = verifier.get_overall_score(pil_img, text_prompt)
else:
logger.warning(f"Unknown verifier type: {verifier_name}")
continue
raw_scores_list[i][verifier_name] = score
except Exception as e:
logger.error(f"Error scoring candidate {i} with {verifier_name}: {str(e)}")
logger.debug(traceback.format_exc())
raw_scores_list[i][verifier_name] = float('-inf')
except Exception as e:
logger.error(f"Error in verifier {verifier_name}: {str(e)}")
logger.debug(traceback.format_exc())
except Exception as e:
logger.error(f"Fatal error in score_candidates: {str(e)}")
logger.debug(traceback.format_exc())
raise
return raw_scores_list
def rank_from_raw_scores(raw_scores_list):
"""
Converts a list of raw score dictionaries into a ranked list
using the existing ranking mechanism.
"""
# Build a verifier-to-scores dictionary from the raw_scores_list
results_by_verifier = {}
for candidate_scores in raw_scores_list:
for verifier_name, score in candidate_scores.items():
if verifier_name not in results_by_verifier:
results_by_verifier[verifier_name] = []
results_by_verifier[verifier_name].append(score)
num_candidates = len(raw_scores_list)
return rank_candidates(results_by_verifier, num_candidates)
class InferenceTimeScaler:
@classmethod
def INPUT_TYPES(s):
return {
"required": {
"model": ("MODEL", {"tooltip": "The model used for denoising the input latent."}),
"seed": ("INT", {"default": 0, "min": 0, "max": 0xffffffffffffffff, "tooltip": "The random seed used for creating the noise."}),
"steps": ("INT", {"default": 20, "min": 1, "max": 10000, "tooltip": "The number of steps used in the denoising process."}),
"cfg": ("FLOAT", {"default": 1.0, "min": 0.0, "max": 100.0, "step": 0.1, "round": 0.01, "tooltip": "The Classifier-Free Guidance scale balances creativity and adherence to the prompt. Higher values result in images more closely matching the prompt; however, too high values may negatively impact quality."}),
"sampler_name": (comfy.samplers.KSampler.SAMPLERS, {"tooltip": "The sampling algorithm used. This can affect the quality, speed, and style of the generated output."}),
"scheduler": (comfy.samplers.KSampler.SCHEDULERS, {"tooltip": "The scheduler controls how noise is gradually removed to form the image."}),
"positive": ("CONDITIONING", {"tooltip": "The conditioning describing the attributes to include in the image."}),
"negative": ("CONDITIONING", {"tooltip": "The conditioning describing the attributes to exclude from the image."}),
"latent_image": ("LATENT", {"tooltip": "The latent image to denoise."}),
"denoise": ("FLOAT", {"default": 1.0, "min": 0.0, "max": 1.0, "step": 0.01, "tooltip": "The amount of denoising applied; lower values maintain more of the structure of the initial image."}),
"text_prompt_to_compare": ("STRING", {"default": "", "multiline": True, "tooltip": "A text prompt used for comparing against generated images."}),
"search_budget": ("INT", {"default": 5, "min": 1, "max": 10000, "tooltip": "The number of random noise samples to generate (i.e., the search budget)."}),
"vae": ("VAE", {"tooltip": "The VAE model used for decoding the latent image."}),
"top_k": ("INT", {"default": 3, "min": 1, "max": 100, "tooltip": "The top k image/score pairs to return."}),
"model": ("MODEL", {"tooltip": "Denoising model."}),
"vae": ("VAE", {"tooltip": "VAE model for decoding latents."}),
"seed": ("INT", {"default": 0, "min": 0, "max": 0xFFFFFFFFFFFFFFFF, "tooltip": "Random seed."}),
"steps": ("INT", {"default": 20, "min": 1, "max": 10000, "tooltip": "Number of denoising steps to apply during each forward evaluation."}),
"cfg": ("FLOAT", {"default": 1.0, "min": 0.0, "max": 100.0, "step": 0.1, "round": 0.01, "tooltip": "Classifier-Free Guidance Scale."}),
"sampler_name": (comfy.samplers.KSampler.SAMPLERS, {"tooltip": "Sampling algorithm to be used during each forward evaluation."}),
"scheduler": (comfy.samplers.KSampler.SCHEDULERS, {"tooltip": "Noise removal scheduler."}),
"positive": ("CONDITIONING", {"tooltip": "Positive prompt conditioning."}),
"negative": ("CONDITIONING", {"tooltip": "Negative prompt conditioning."}),
"latent_image": ("LATENT", {"tooltip": "Latent image to be denoised."}),
"denoise": ("FLOAT", {"default": 1.0, "min": 0.0, "max": 1.0, "step": 0.01, "tooltip": "Amount of denoising."}),
"search_algorithm": (["random", "zero-order"], {"default": "random", "tooltip": "Select the search algorithm: 'random' for standard random search or 'zero-order' for gradient-free local search."}),
"text_prompt_to_compare": ("STRING", {"default": "", "multiline": True, "tooltip": "Text prompt for verifier(s)."}),
"search_rounds": ("INT", {"default": 5, "min": 1, "max": 10000, "tooltip": "Number of search rounds (random seeds for random search, or iterations for zero-order search)."}),
"view_top_k": ("INT", {"default": 3, "min": 1, "max": 100, "tooltip": "Return grid view of the top-k images."}),
"num_neighbors": ("INT", {"default": 4, "min": 1, "max": 100, "tooltip": "Number of neighbors to sample per iteration in zero-order search (only used if search_algorithm is 'zero-order')."}),
"lambda_threshold": ("FLOAT", {"default": 0.90, "min": 0.0, "max": 1.0, "step": 0.05, "round": 0.001, "tooltip": "Perturbation step size for zero-order search (only used if search_algorithm is 'zero-order')."})
},
"optional": {
"clip_score_verifier": ("STRING", {"default": "openai/clip-vit-base-patch32", "tooltip": "Optional Hugging Face CLIP model identifier used for verifying the generated image quality."}),
"clip_score_weight": ("FLOAT", {"default": 1, "min": 0, "max": 1, "tooltip": "The weight of the clip verifier to apply "}),
"image_reward_verifier": ("STRING", {"default": "ImageReward-v1.0", "tooltip": "Optional Image Reward model used for verifying the generated image quality."}),
"image_reward_weight": ("FLOAT", {"default": 1, "min": 0, "max": 1, "tooltip": "The weight of the iamge rewqrd to apply "})
"loaded_clip_score_verifier": ("CS_VERIFIER", {"tooltip": "HF CLIP model identifier."}),
"loaded_image_reward_verifier": ("IR_VERIFIER", {"tooltip": "ImageReward model identifier."}),
"loaded_qwen_verifier": ("QWN_VERIFIER", {"tooltip": "Qwen model identifier."})
}
}
RETURN_TYPES = ("IMAGE", "IMAGE", "STRING")
RETURN_NAMES = ("Best Image", "Top-k Grid", "Top-k Score(s)")
OUTPUT_TOOLTIPS = ("A grid of the top k images from the random search, and a JSON string with their verifier scores.",)
OUTPUT_TOOLTIPS = ("Best single image, grid of the top-k images, and their scores in JSON.",)
FUNCTION = "execute"
CATEGORY = "InferenceTimeScaling"
DESCRIPTION = (
"Performs inference-time optimization to find the best image matching your text prompt. "
"Supports two search algorithms:\n"
"1. Random Search: Generates multiple images with different random seeds\n"
"2. Zero-Order Search: Performs gradient-free local optimization\n\n"
"Uses an ensemble of AI verifiers (CLIP, ImageReward, Qwen-VL) to score and rank the generated images. "
"Returns the best image, a grid of top-k results, and detailed scoring information."
)
CATEGORY = "maxtest/sampling"
DESCRIPTION = ("Uses the provided model, conditioning, and VAE to denoise the latent image. "
"Performs random search over noise candidates by sampling different noises, decodes each candidate image, "
"evaluates its quality using a verifier (if provided), and returns the top k candidates based on the verifier score.")
def execute(self, model, vae, seed, steps, cfg, sampler_name, scheduler, positive, negative, latent_image, denoise,
text_prompt_to_compare, search_rounds, view_top_k, loaded_clip_score_verifier=None, loaded_image_reward_verifier=None,
search_algorithm="random", num_neighbors=4, lambda_threshold=0.01, loaded_qwen_verifier=None):
"""
Main execution method for inference time scaling.
"""
try:
# Only handling batch size of 1 for now
if latent_image["samples"].size(0) != 1:
raise ValueError(f"Expected latent image batch size of 1, got {latent_image['samples'].size(0)}")
logger.info(f"Starting InferenceTimeScaler with algorithm: {search_algorithm}")
logger.info(f"Search rounds: {search_rounds}, Top-k: {view_top_k}")
def execute(self,
model,
vae,
seed,
steps,
cfg,
sampler_name,
scheduler,
positive,
negative,
latent_image,
denoise,
text_prompt_to_compare,
search_budget,
top_k,
clip_score_verifier=None,
image_reward_verifier=None,
clip_score_weight=1.0,
image_reward_weight=1.0
):
# TODO Move to innit
device = "cuda" if torch.cuda.is_available() else "cpu"
if not text_prompt_to_compare:
logger.warning("Empty text prompt provided")
candidate_results = []
use_zero_order = (search_algorithm == "zero-order")
# Validate inputs
if steps < 1:
raise ValueError("Steps must be >= 1")
if cfg < 0:
raise ValueError("CFG must be >= 0")
if denoise < 0 or denoise > 1:
raise ValueError("Denoise must be between 0 and 1")
verifiers = {}
weights = {}
if clip_score_verifier:
clip_model = CLIPModel.from_pretrained(clip_score_verifier)
clip_processor = CLIPProcessor.from_pretrained(clip_score_verifier)
clip_model.to(device)
verifiers['clip'] = (clip_model, clip_processor)
weights['clip'] = clip_score_weight
# Store loaded verifier models
verifier_names = {
"clip": loaded_clip_score_verifier,
"image_reward": loaded_image_reward_verifier,
"qwen_vlm_verifier": loaded_qwen_verifier
}
if image_reward_verifier:
image_reward_model = reward.load(image_reward_verifier)
verifiers['image_reward'] = image_reward_model
weights['image_reward'] = image_reward_weight
active_verifiers = sum(1 for v in verifier_names.values() if v is not None)
if active_verifiers == 0:
raise ValueError("No verifiers provided - at least one verifier is required")
logger.info(f"Using {active_verifiers} active verifiers")
for i in range(search_budget):
if use_zero_order:
result = self._execute_zero_order(
model, vae, seed, steps, cfg, sampler_name, scheduler,
positive, negative, latent_image, denoise, text_prompt_to_compare,
verifier_names, search_rounds, num_neighbors, lambda_threshold, view_top_k
)
else:
result = self._execute_random_search(
model, vae, seed, steps, cfg, sampler_name, scheduler,
positive, negative, latent_image, denoise, text_prompt_to_compare,
verifier_names, search_rounds, view_top_k
)
logger.info("InferenceTimeScaler execution completed successfully")
return result
except Exception as e:
logger.error(f"Error in InferenceTimeScaler: {str(e)}")
logger.debug(traceback.format_exc())
# Return a blank image and error message
error_tensor = torch.zeros((1, 64, 64, 3), dtype=torch.float32)
error_json = json.dumps({"error": str(e)})
return (error_tensor, error_tensor, error_json)
def _execute_zero_order(self, model, vae, seed, steps, cfg, sampler_name, scheduler,
positive, negative, latent_image, denoise, text_prompt_to_compare,
verifier_names, search_rounds, num_neighbors, lambda_threshold, view_top_k):
"""
Execute zero-order optimization search algorithm
"""
logger.info(f"Starting zero-order search with {search_rounds} rounds")
batch_inds = latent_image.get("batch_index", None)
pivot_noise = comfy.sample.prepare_noise(latent_image["samples"], seed, batch_inds)
pivot_included_in_pool = False
# Initialize a pool to accumulate (candidate_tensor, raw_scores) pairs
candidate_pool = []
for round_idx in range(search_rounds):
# Generate neighbors around the pivot noise
neighbors = generate_neighbors(pivot_noise, threshold=lambda_threshold, num_neighbors=num_neighbors)
# Prepend the pivot as the "zeroth" neighbor
pivot_expanded = pivot_noise.unsqueeze(1) # shape: [B,1,C,H,W]
neighbors = torch.cat([pivot_expanded, neighbors], dim=1) # shape: [B, num_neighbors+1, C,H,W]
candidate_noises = []
candidate_decoded_tensors = []
for i in range(num_neighbors + 1):
candidate_noises.append(neighbors[:, i]) # each candidate is of shape [B, C, H, W]
# Decode all candidate noises for this round
for noise_candidate in candidate_noises:
samples, = common_ksampler(
model, seed, steps, cfg, sampler_name, scheduler,
positive, negative, latent_image, denoise,
override_noise=noise_candidate
)
decoded = vae.decode(samples["samples"])
if decoded.ndim == 5:
b, c, h, w, d = decoded.shape
decoded = decoded.view(-1, h, w, d)
candidate_decoded_tensors.append(decoded[0:1])
# score the candidates
raw_scores = score_candidates(candidate_decoded_tensors, text_prompt_to_compare, verifier_names)
ranked_candidates = rank_from_raw_scores(raw_scores)
best_idx = ranked_candidates[0]["index"]
for i, (tensor_img, candidate_raw_scores) in enumerate(zip(candidate_decoded_tensors, raw_scores)):
if i == 0: # pivot candidate
if not pivot_included_in_pool:
candidate_pool.append((tensor_img, candidate_raw_scores))
pivot_included_in_pool = True
else:
candidate_pool.append((tensor_img, candidate_raw_scores))
# Rejecting a round if the pivot is best
if best_idx == 0:
# The original pivot outperformed all neighbors so we reject this round
pivot_noise = comfy.sample.prepare_noise(latent_image["samples"], seed + round_idx + 1000, batch_inds)
pivot_included_in_pool = False
else:
# Update the pivot to be the best candidate's noise from this round
pivot_noise = candidate_noises[best_idx]
pivot_included_in_pool = True
# Final ranking from the candidate pool
pool_raw_scores = [scores for (_, scores) in candidate_pool]
ranked_pool = rank_from_raw_scores(pool_raw_scores)
# Reorder candidate_pool by the ranking results
candidate_pool_sorted = [candidate_pool[entry["index"]][0] for entry in ranked_pool]
top_k_tensors = candidate_pool_sorted[:view_top_k]
best_tensor = top_k_tensors[0]
# Build ranking result list for JSON output
top_k_results = ranked_pool[:view_top_k]
# Create grid of top-k images for visualization purposes
if len(top_k_tensors) == 0:
grid_image = torch.zeros((1, 64, 64, 3), dtype=torch.float32)
else:
images_for_grid = [t.squeeze(0).permute(2, 0, 1) for t in top_k_tensors]
grid = make_grid(torch.stack(images_for_grid), nrow=len(images_for_grid))
grid_image = grid.permute(1, 2, 0).unsqueeze(0)
results_json = {
"results": top_k_results
}
scores_json_str = json.dumps(results_json, indent=2)
return (best_tensor, grid_image, scores_json_str)
def _execute_random_search(self, model, vae, seed, steps, cfg, sampler_name, scheduler,
positive, negative, latent_image, denoise, text_prompt_to_compare,
verifier_names, search_rounds, view_top_k):
"""
Execute random search algorithm
"""
logger.info(f"Starting random search with budget {search_rounds}")
candidate_tensors = []
for i in range(search_rounds):
new_seed = seed + i + 1
samples, = common_ksampler(model, new_seed, steps, cfg, sampler_name, scheduler, positive, negative, latent_image, denoise=denoise)
candidate_images = vae.decode(samples["samples"])
if len(candidate_images.shape) == 5:
candidate_images = candidate_images.reshape(-1, candidate_images.shape[-3], candidate_images.shape[-2], candidate_images.shape[-1])
candidate_image = candidate_images[0:1] # Using the first image of the batch.
samples, = common_ksampler(model, new_seed, steps, cfg, sampler_name, scheduler, positive, negative, latent_image, denoise)
decoded = vae.decode(samples["samples"])
if decoded.ndim == 5:
b, c, h, w, d = decoded.shape
decoded = decoded.view(-1, h, w, d)
single_candidate = decoded[0:1]
candidate_tensors.append(single_candidate)
# Convert from tensor to PIL Image
# Remove the batch dimension: [1, H, W, 3] -> [H, W, 3]
image_tensor = candidate_image.squeeze(0)
# Permute to [C, H, W]
image_tensor = image_tensor.permute(2, 0, 1)
# Convert to PIL Image
candidate_pil_image = ToPILImage()(image_tensor)
# scoring and ranking
raw_scores = score_candidates(candidate_tensors, text_prompt_to_compare, verifier_names)
final_ranked_results = rank_from_raw_scores(raw_scores)
top_k_results = final_ranked_results[:min(view_top_k, len(final_ranked_results))]
top_k_indices = [r["index"] for r in top_k_results]
top_k_tensors = [candidate_tensors[i] for i in top_k_indices]
best_tensor = candidate_tensors[final_ranked_results[0]["index"]]
# Score the candidate
combined_score, individual_scores = compute_combined_verifier_score(candidate_pil_image, text_prompt_to_compare, verifiers, weights)
candidate_results.append((candidate_image, combined_score))
candidate_results.sort(key=lambda x: x[1], reverse=True)
top_candidates = candidate_results[:min(top_k, len(candidate_results))]
images_list = [img for (img, score) in top_candidates]
scores_list = [score for (img, score) in top_candidates]
# Prepare the images for grid display.
images_for_grid = [img.squeeze(0).permute(2, 0, 1) for img in images_list]
grid_image = make_grid(torch.stack(images_for_grid), nrow=top_k)
grid_image = grid_image.permute(1, 2, 0).unsqueeze(0)
scores_json = json.dumps({"results": [{"score": score} for score in scores_list]})
best_candidate = images_list[0]
return (best_candidate, grid_image, scores_json)
# Create grid of top-k images for visualization purposes
if len(top_k_tensors) == 0:
grid_image = torch.zeros((1, 64, 64, 3), dtype=torch.float32)
else:
images_for_grid = [t.squeeze(0).permute(2, 0, 1) for t in top_k_tensors]
grid = make_grid(torch.stack(images_for_grid), nrow=len(images_for_grid))
grid_image = grid.permute(1, 2, 0).unsqueeze(0)
results_json = {
"results": top_k_results
}
scores_json_str = json.dumps(results_json, indent=2)
return (best_tensor, grid_image, scores_json_str)
class LoadQwenVLMVerifier:
@classmethod
def INPUT_TYPES(cls):
return {
"required": {
"qwen_verifier_id": (["Qwen/Qwen2.5-VL-7B-Instruct", None], {
"default": "Qwen/Qwen2.5-VL-7B-Instruct",
"tooltip": "Identifier for the Qwen VLM model."
}),
"device": ("STRING", {
"default": "cuda" if torch.cuda.is_available() else "cpu",
"tooltip": "Device to load the model onto."
})
}
}
RETURN_TYPES = ("QWN_VERIFIER",)
RETURN_NAMES = ("qwen_verifier_instance",)
FUNCTION = "execute"
CATEGORY = "InferenceTimeScaling"
DESCRIPTION = "Loads the Qwen VLM verifier model. Downloads it if necessary."
def execute(self, qwen_verifier_id, device):
# Construct a local comfyui checkpoint path for the model
model_checkpoint = os.path.join(folder_paths.models_dir, "LLM", os.path.basename(qwen_verifier_id))
if not os.path.exists(model_checkpoint):
snapshot_download(
repo_id=qwen_verifier_id,
local_dir=model_checkpoint,
local_dir_use_symlinks=False,
)
verifier_instance = QwenVLMVerifier(qwen_verifier_id, device)
return (verifier_instance,)
class CLIPScoreVerifier:
def __init__(self, model, processor, device):
self.model = model
self.processor = processor
self.device = device
def score(self, text_prompt, pil_img):
# Prepare inputs and move to the correct device
inputs = self.processor(text=[text_prompt], images=pil_img, return_tensors="pt", padding=True)
inputs = {k: v.to(self.device) for k, v in inputs.items()}
# Compute features
text_emb = self.model.get_text_features(inputs["input_ids"], attention_mask=inputs["attention_mask"])
image_emb = self.model.get_image_features(pixel_values=inputs["pixel_values"])
# Normalize and compute cosine similarity
text_emb = F.normalize(text_emb, dim=-1)
image_emb = F.normalize(image_emb, dim=-1)
return F.cosine_similarity(text_emb, image_emb).item()
class LoadCLIPScoreVerifier:
@classmethod
def INPUT_TYPES(cls):
return {
"required": {
"clip_verifier_id": (["openai/clip-vit-base-patch32", "openai/clip-vit-large-patch14", None], {
"default": "openai/clip-vit-base-patch32",
"tooltip": "Identifier for the CLIP model."
}),
"device": ("STRING", {
"default": "cuda" if torch.cuda.is_available() else "cpu",
"tooltip": "Device to load the model onto."
})
}
}
RETURN_TYPES = ("CS_VERIFIER",)
RETURN_NAMES = ("clip_verifier_instance",)
FUNCTION = "execute"
CATEGORY = "InferenceTimeScaling"
DESCRIPTION = "Loads the CLIP verifier model and processor."
def execute(self, clip_verifier_id, device):
clip_model = CLIPModel.from_pretrained(clip_verifier_id)
clip_processor = CLIPProcessor.from_pretrained(clip_verifier_id)
clip_model.to(device)
verifier_instance = CLIPScoreVerifier(clip_model, clip_processor, device)
return (verifier_instance,)
class ImageRewardVerifier:
def __init__(self, model, device):
self.model = model
self.device = device
def score(self, text_prompt, pil_img):
return self.model.score(text_prompt, pil_img)
class LoadImageRewardVerifier:
@classmethod
def INPUT_TYPES(cls):
return {
"required": {
"ir_verifier_id": (["ImageReward-v1.0", None], {
"default": "ImageReward-v1.0",
"tooltip": "Identifier for the ImageReward model."
}),
"device": ("STRING", {
"default": "cuda" if torch.cuda.is_available() else "cpu",
"tooltip": "Device to load the model onto."
})
}
}
RETURN_TYPES = ("IR_VERIFIER",)
RETURN_NAMES = ("image_reward_verifier_instance",)
FUNCTION = "execute"
CATEGORY = "InferenceTimeScaling"
DESCRIPTION = "Loads the ImageReward verifier model."
def execute(self, ir_verifier_id, device):
ir_model = reward.load(ir_verifier_id)
try:
ir_model.to(device)
except Exception:
# Some ImageReward models may not support .to(device) directly
pass
verifier_instance = ImageRewardVerifier(ir_model, device)
return (verifier_instance,)
# Node registration
NODE_CLASS_MAPPINGS = {
"MaximKSampler": MaximKSampler
"InferenceTimeScaler": InferenceTimeScaler,
"LoadQwenVLMVerifier": LoadQwenVLMVerifier,
"LoadCLIPScoreVerifier": LoadCLIPScoreVerifier,
"LoadImageRewardVerifier": LoadImageRewardVerifier
}
NODE_DISPLAY_NAME_MAPPINGS = {
"MaximKSampler": "MaximKSampler"
"InferenceTimeScaler": "Inference Time Scaler",
"LoadQwenVLMVerifier": "Load Qwen VLM Verifier",
"LoadCLIPScoreVerifier": "Load CLIPScore Verifier",
"LoadImageRewardVerifier": "Load ImageReward Verifier"
}