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easygoing0114-ComfyUI-clipt…/nodes.py
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easygoing0114 fa4b788000 new file: LICENSE
new file:   README.md
	new file:   __init__.py
	new file:   gitignore.txt
	new file:   nodes.py
	new file:   pyproject.toml
2026-08-09 08:32:31 +09:00

374 lines
15 KiB
Python

import logging
import os
import re
from types import SimpleNamespace
from typing import Optional, Tuple
import torch
import torch.nn as nn
import torch.nn.functional as F
from huggingface_hub import hf_hub_download
from safetensors import safe_open
import comfy.model_management
def _fix_punctuation_spacing(text: str) -> str:
"""Remove stray whitespace before commas and periods left over from
CLIPTokenizer's BPE decoding (e.g. "cats , dogs ." -> "cats, dogs.")."""
return re.sub(r"\s+([,.])", r"\1", text)
class DecoderBlock(nn.Module):
def __init__(self, embed_dim: int, num_heads: int):
super().__init__()
self.norm1 = nn.LayerNorm(embed_dim)
self.self_attn = nn.MultiheadAttention(
embed_dim=embed_dim, num_heads=num_heads, batch_first=True
)
self.norm2 = nn.LayerNorm(embed_dim)
self.cross_attn = nn.MultiheadAttention(
embed_dim=embed_dim, num_heads=num_heads, batch_first=True
)
self.norm3 = nn.LayerNorm(embed_dim)
self.mlp = nn.Sequential(
nn.Linear(embed_dim, embed_dim * 4),
nn.GELU(),
nn.Identity(),
nn.Linear(embed_dim * 4, embed_dim),
)
def forward(self, x: torch.Tensor, memory: torch.Tensor, self_attn_mask: torch.Tensor):
# self attention with mask
residual = x
x = self.norm1(x)
attn_output, _ = self.self_attn(
query=x, key=x, value=x, attn_mask=self_attn_mask, need_weights=False, is_causal=True
)
x = residual + attn_output
# cross attention
residual = x
x = self.norm2(x)
attn_output, _ = self.cross_attn(query=x, key=memory, value=memory, need_weights=False)
x = residual + attn_output
# FFN
residual = x
x = self.norm3(x)
x = residual + self.mlp(x)
return x
class Captioner(nn.Module):
def __init__(self, config, vision_embed_dim: int, vocab_size: int):
super().__init__()
self.hidden_dim = config.hidden_dim
self.max_length = config.max_length
# projection from ViT dimension to decoder dimension
self.projection = nn.Linear(vision_embed_dim, self.hidden_dim)
self.memory_pos_embedding = nn.Parameter(torch.zeros(1, 257, self.hidden_dim))
# decoder layers
self.layers = nn.ModuleList(
[DecoderBlock(config.hidden_dim, config.num_heads) for _ in range(config.num_blocks)]
)
causal_mask = nn.Transformer.generate_square_subsequent_mask(self.max_length)
self.register_buffer("causal_mask", causal_mask, persistent=False)
class CLIPtionModel(nn.Module):
def __init__(self, config, clip, clip_vision, device=None):
super().__init__()
if not hasattr(clip, "cond_stage_model"):
raise ValueError("CLIP is missing from model checkpoint")
if not hasattr(clip.cond_stage_model, "clip_l"):
raise ValueError("Must use model which includes CLIP-L")
# store CLIP model references
self.clip_text = clip
self.clip_vision = clip_vision
# use specified device, or fall back to ComfyUI default at runtime
self.inference_device = device
self.tokenizer = clip.tokenizer.clip_l.tokenizer
self.text_model = clip.cond_stage_model.clip_l.transformer.text_model
# clip.cond_stage_model.clip_l.transformer.text_projection is empty
# so load a copy from the CLIPtion safetensors file instead
self.text_projection = nn.Linear(768, 768, bias=False)
# create caption decoder
self.captioner = Captioner(config, 1024, self.tokenizer.vocab_size)
# use CLIP's token embeddings for output projection
clip_embed_weight = self.text_model.embeddings.token_embedding.weight
self.output_projection = nn.Linear(
self.captioner.hidden_dim, self.tokenizer.vocab_size, bias=False
)
self.output_projection.weight = nn.Parameter(clip_embed_weight.clone())
def generate_beam(self, images: torch.Tensor, beam_width: int = 4) -> list:
device = self.inference_device or comfy.model_management.get_torch_device()
image_features, image_embeds = self._images_to_embeds(images, device)
captions = []
for image_idx in range(image_features.size(0)):
features = image_features[image_idx].unsqueeze(0)
candidates = self._beam_search(
features, image_embeds[image_idx : image_idx + 1], device, beam_width
)
# pick highest scoring candidate
candidates.sort(key=lambda x: x[0])
for score, text in candidates:
logging.debug(f"({score:.3f}) {text}")
captions.append(candidates[-1][1])
return captions
def _beam_search(
self,
image_features: torch.Tensor,
image_embed: torch.Tensor,
device: torch.device,
beam_width: int,
):
tokenizer = self.tokenizer
captioner = self.captioner
token_embedding = self.text_model.embeddings.token_embedding
pos_embedding = self.text_model.embeddings.position_embedding
vocab_size = tokenizer.vocab_size
# project image features
# determine dtype from captioner weights to handle FP32 models correctly
model_dtype = next(captioner.parameters()).dtype
memory = captioner.projection(image_features.to(dtype=model_dtype))
memory = memory + captioner.memory_pos_embedding
# start with beam_width copies of BOS token
current_tokens = torch.full(
(beam_width, 1), tokenizer.bos_token_id, dtype=torch.long, device=device
)
scores = torch.zeros(beam_width, device=device)
for step in range(captioner.max_length - 2):
# embed current tokens
token_embeddings = token_embedding(current_tokens)
positions = torch.arange(current_tokens.size(1), device=device)
pos_embeddings = pos_embedding(positions)
# cast to model dtype to handle FP32/FP16 mismatch
x = (token_embeddings + pos_embeddings).to(dtype=model_dtype)
# run decoder layers
seq_len = x.size(1)
mask = captioner.causal_mask[:seq_len, :seq_len]
for layer in captioner.layers:
x = layer(x, memory.repeat(beam_width, 1, 1), self_attn_mask=mask)
# get next token log probabilities
logits = self.output_projection(x[:, -1:])
log_probs = F.log_softmax(logits, dim=-1)
if step == 0:
# pick top-k tokens for first step
scores = log_probs.squeeze(1)[0]
scores, indices = scores.topk(beam_width)
current_tokens = torch.cat(
[current_tokens[0:1].repeat(beam_width, 1), indices.unsqueeze(1)], dim=1
)
else:
# calculate scores for next tokens [beam_width x vocab_size]
next_scores = scores.unsqueeze(1) + log_probs.squeeze(1)
# force sequences to continue EOS after first one
prev_is_eos = current_tokens[:, -1] == tokenizer.eos_token_id
vocab_mask = torch.zeros_like(next_scores)
vocab_mask[prev_is_eos] = float("-inf")
vocab_mask[prev_is_eos, tokenizer.eos_token_id] = 0
next_scores = next_scores + vocab_mask
# pick top beam_width sequences
next_scores = next_scores.view(-1)
scores, indices = next_scores.topk(beam_width)
beam_indices = indices // vocab_size # which sequence each came from
token_indices = indices % vocab_size # which token to append
current_tokens = torch.cat(
[current_tokens[beam_indices], token_indices.unsqueeze(1)], dim=1
)
# check if all beams ended with EOS
if (current_tokens[:, -1] == tokenizer.eos_token_id).all():
break
# add final EOS token
current_tokens = torch.cat(
[current_tokens, torch.full((beam_width, 1), tokenizer.eos_token_id, device=device)],
dim=1,
)
# rank final candidates by CLIP similarity
candidates = []
for idx in range(beam_width):
tokens = current_tokens[idx]
# trim everything after the first EOS token (inclusive) before decoding
eos_positions = (tokens == tokenizer.eos_token_id).nonzero(as_tuple=True)[0]
if len(eos_positions) > 0:
tokens = tokens[: eos_positions[0]]
text = tokenizer.decode(tokens, skip_special_tokens=True, clean_up_tokenization_spaces=True)
text = _fix_punctuation_spacing(text)
text_embeds = self._text_to_embed(text, device)
clip_sim = torch.sum(image_embed * text_embeds, dim=-1)[0]
candidates.append((clip_sim.item(), text))
return candidates
def _images_to_embeds(self, images: torch.Tensor, device: torch.device) -> Tuple[torch.Tensor, torch.Tensor]:
if images.size(-1) == 1:
images = images.repeat(1, 1, 1, 3)
elif images.size(-1) == 4:
images = images[..., :3]
outputs = self.clip_vision.encode_image(images)
# features go into the FP16 CLIPtion decoder, so cast to FP16
features = outputs.last_hidden_state.to(device, dtype=torch.float16)
if features.size(2) != 1024:
raise ValueError(
f"Expected image features to have 1024 dimensions but got {features.size(2)}. Please ensure you are using CLIP L."
)
# embeds are used only for CLIP similarity scoring, preserve original dtype (FP32) for accuracy
embeds = outputs.image_embeds.to(device)
embeds = embeds / embeds.norm(dim=-1, keepdim=True)
return features, embeds
def _text_to_embed(self, text: str, device: torch.device) -> torch.Tensor:
# load CLIP model and disable final projection since that's missing from comfy checkpoints
self.clip_text.load_model()
self.clip_text.cond_stage_model.reset_clip_options()
self.clip_text.cond_stage_model.set_clip_options({"projected_pooled": False})
# calculate text embedding
tokens = self.clip_text.tokenize(text)
clip_l = self.clip_text.cond_stage_model.clip_l
_, pooled = clip_l.encode_token_weights(tokens["l"])
# preserve original dtype (FP32) for accurate CLIP similarity scoring
text_embeds = self.text_projection(pooled.to(device))
text_embeds = text_embeds / text_embeds.norm(dim=-1, keepdim=True)
return text_embeds
class CLIPtionBeamSearchIntegrated:
"""
Combined CLIPtion loader + beam search node.
Loads the CLIPtion decoder on demand at caption time rather than at
workflow-load time, and can optionally unload it from VRAM afterwards.
The CLIPtion safetensors weights are kept on CPU between runs so that
re-loading does not require a disk read.
"""
CATEGORY = "pharmapsychotic"
FUNCTION = "caption"
OUTPUT_IS_LIST = (True,)
RETURN_TYPES = ("STRING",)
# CLIPtion decoder config (fixed for the released checkpoint)
_CAPTIONER_CONFIG = SimpleNamespace(hidden_dim=768, num_heads=8, num_blocks=6, max_length=77)
_SAFETENSORS_FILE = "CLIPtion_20241219_fp16.safetensors"
_HF_REPO_ID = "pharmapsychotic/CLIPtion"
_HF_REVISION = "15ee8cb77a902616478a033332011ff640e72277"
def __init__(self):
self._model: Optional[CLIPtionModel] = None
@classmethod
def INPUT_TYPES(s):
return {
"required": {
"clip": ("CLIP", {"tooltip": "CLIP text encoder (must include CLIP-L)."}),
"clip_vision": ("CLIP_VISION", {"tooltip": "CLIP vision encoder (must be CLIP-L)."}),
"image": ("IMAGE",),
"beam_width": (
"INT",
{"default": 4, "min": 1, "max": 64, "tooltip": "Number of beams to maintain during search."},
),
"unload_after_run": (
"BOOLEAN",
{"default": False, "tooltip": "Unload CLIPtion decoder from VRAM after captioning."},
),
},
"optional": {
"device": (["default", "cpu"], {"advanced": True}),
},
}
def caption(self, clip, clip_vision, image: torch.Tensor, beam_width: int = 4,
unload_after_run: bool = False, device: str = "default"):
try:
self._load_model(clip, clip_vision, device)
with torch.inference_mode():
captions = self._model.generate_beam(image, beam_width)
finally:
if unload_after_run:
self._unload_model()
return (captions,)
def _load_model(self, clip, clip_vision, device: str):
"""Load CLIPtion decoder from disk and move to target device."""
if self._model is not None:
return
base_path = os.path.dirname(os.path.abspath(__file__))
local_path = os.path.join(base_path, self._SAFETENSORS_FILE)
if os.path.exists(local_path):
model_path = local_path
else:
model_path = hf_hub_download(
repo_id=self._HF_REPO_ID, filename=self._SAFETENSORS_FILE, revision=self._HF_REVISION
)
state_dict = {}
with safe_open(model_path, framework="pt", device="cpu") as f:
for key in f.keys():
state_dict[key] = f.get_tensor(key)
tp_dict = {"weight": state_dict.pop("text_projection.weight")}
inference_device = torch.device("cpu") if device == "cpu" else None
model = CLIPtionModel(self._CAPTIONER_CONFIG, clip, clip_vision, device=inference_device)
model.captioner.load_state_dict(state_dict)
model.text_projection.load_state_dict(tp_dict)
model.eval()
load_device = inference_device or comfy.model_management.get_torch_device()
model.to(load_device, dtype=torch.float16)
# keep text_projection in FP32 to preserve CLIP similarity scoring accuracy
model.text_projection.to(dtype=torch.float32)
self._model = model
logging.info(f"CLIPtionBeamSearchIntegrated: decoder loaded on {load_device}")
def _unload_model(self):
"""Remove the CLIPtion decoder from VRAM and CPU RAM completely."""
if self._model is None:
return
del self._model
self._model = None
if torch.cuda.is_available():
torch.cuda.empty_cache()
logging.info("CLIPtionBeamSearchIntegrated: decoder unloaded")
NODE_CLASS_MAPPINGS = {
"CLIPtionBeamSearchIntegrated": CLIPtionBeamSearchIntegrated,
}
NODE_DISPLAY_NAME_MAPPINGS = {
"CLIPtionBeamSearchIntegrated": "CLIPtion Beam Search (Integrated)",
}