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LEANN/apps/multimodal/vision-based-pdf-multi-vector/multi-vector-leann-similarity-map.py
2025-09-22 20:12:02 +00:00

450 lines
16 KiB
Python

## Jupyter-style notebook script
#%%
# uv pip install matplotlib qwen_vl_utils
import os
import re
import sys
from pathlib import Path
from typing import List, Optional, Tuple, cast, Any
import numpy as np
from PIL import Image
from tqdm import tqdm
def _ensure_repo_paths_importable(current_file: str) -> None:
"""Make local leann packages importable without installing (mirrors multi-vector-leann.py)."""
_repo_root = Path(current_file).resolve().parents[3]
_leann_core_src = _repo_root / "packages" / "leann-core" / "src"
_leann_hnsw_pkg = _repo_root / "packages" / "leann-backend-hnsw"
if str(_leann_core_src) not in sys.path:
sys.path.append(str(_leann_core_src))
if str(_leann_hnsw_pkg) not in sys.path:
sys.path.append(str(_leann_hnsw_pkg))
_ensure_repo_paths_importable(__file__)
from leann_multi_vector import LeannMultiVector # noqa: E402
#%%
# Config
os.environ["TOKENIZERS_PARALLELISM"] = "false"
QUERY = "How does DeepSeek-V2 compare against the LLaMA family of LLMs?"
MODEL: str = "colqwen2" # "colpali" or "colqwen2"
# Data source: set to True to use the Hugging Face dataset example (recommended)
USE_HF_DATASET: bool = True
DATASET_NAME: str = "weaviate/arXiv-AI-papers-multi-vector"
DATASET_SPLIT: str = "train"
MAX_DOCS: Optional[int] = None # limit number of pages to index; None = all
# Local pages (used when USE_HF_DATASET == False)
PDF: Optional[str] = None # e.g., "./pdfs/2004.12832v2.pdf"
PAGES_DIR: str = "./pages"
# Index + retrieval settings
INDEX_PATH: str = "./indexes/colvision.leann"
TOPK: int = 1
FIRST_STAGE_K: int = 50
REBUILD_INDEX: bool = False
# Artifacts
SAVE_TOP_IMAGE: Optional[str] = "./figures/retrieved_page.png"
SIMILARITY_MAP: bool = True
SIM_TOKEN_IDX: int = -1 # -1 means auto-select the most salient token
SIM_OUTPUT: str = "./figures/similarity_map.png"
ANSWER: bool = True
MAX_NEW_TOKENS: int = 128
#%%
# Helpers
def _natural_sort_key(name: str) -> int:
m = re.search(r"\d+", name)
return int(m.group()) if m else 0
def _load_images_from_dir(pages_dir: str) -> Tuple[List[str], List[Image.Image]]:
filenames = [n for n in os.listdir(pages_dir) if n.lower().endswith((".png", ".jpg", ".jpeg"))]
filenames = sorted(filenames, key=_natural_sort_key)
filepaths = [os.path.join(pages_dir, n) for n in filenames]
images = [Image.open(p) for p in filepaths]
return filepaths, images
def _maybe_convert_pdf_to_images(pdf_path: Optional[str], pages_dir: str, dpi: int = 200) -> None:
if not pdf_path:
return
os.makedirs(pages_dir, exist_ok=True)
try:
from pdf2image import convert_from_path
except Exception as e:
raise RuntimeError("pdf2image is required to convert PDF to images. Install via pip install pdf2image") from e
images = convert_from_path(pdf_path, dpi=dpi)
for i, image in enumerate(images):
image.save(os.path.join(pages_dir, f"page_{i + 1}.png"), "PNG")
def _select_device_and_dtype():
import torch
from colpali_engine.utils.torch_utils import get_torch_device
device_str = (
"cuda"
if torch.cuda.is_available()
else ("mps" if getattr(torch.backends, "mps", None) and torch.backends.mps.is_available() else "cpu")
)
device = get_torch_device(device_str)
# Stable dtype selection to avoid NaNs:
# - CUDA: prefer bfloat16 if supported, else float16
# - MPS: use float32 (fp16 on MPS can produce NaNs in some ops)
# - CPU: float32
if device_str == "cuda":
dtype = torch.bfloat16 if torch.cuda.is_bf16_supported() else torch.float16
try:
torch.backends.cuda.matmul.allow_tf32 = True # Better stability/perf on Ampere+
except Exception:
pass
elif device_str == "mps":
dtype = torch.float32
else:
dtype = torch.float32
return device_str, device, dtype
def _load_colvision(model_choice: str):
import torch
from colpali_engine.models import ColPali
from colpali_engine.models.paligemma.colpali.processing_colpali import ColPaliProcessor
from transformers.utils.import_utils import is_flash_attn_2_available
from colpali_engine.models import ColQwen2, ColQwen2Processor
device_str, device, dtype = _select_device_and_dtype()
if model_choice == "colqwen2":
model_name = "vidore/colqwen2-v1.0"
# On CPU/MPS we must avoid flash-attn and stay eager; on CUDA prefer flash-attn if available
attn_implementation = "flash_attention_2" if (device_str == "cuda" and is_flash_attn_2_available()) else "eager"
model = ColQwen2.from_pretrained(
model_name,
torch_dtype=torch.bfloat16,
device_map=device,
attn_implementation=attn_implementation,
).eval()
processor = ColQwen2Processor.from_pretrained(model_name)
else:
model_name = "vidore/colpali-v1.2"
model = ColPali.from_pretrained(
model_name,
torch_dtype=torch.bfloat16,
device_map=device,
).eval()
processor = cast(ColPaliProcessor, ColPaliProcessor.from_pretrained(model_name))
return model_name, model, processor, device_str, device, dtype
def _embed_images(model, processor, images: List[Image.Image]) -> List[Any]:
import torch
from colpali_engine.utils.torch_utils import ListDataset
from torch.utils.data import DataLoader
# Ensure deterministic eval and autocast for stability
model.eval()
dataloader = DataLoader(
dataset=ListDataset[Image.Image](images),
batch_size=1,
shuffle=False,
collate_fn=lambda x: processor.process_images(x),
)
doc_vecs: List[Any] = []
for batch_doc in dataloader:
with torch.no_grad():
batch_doc = {k: v.to(model.device) for k, v in batch_doc.items()}
# autocast on CUDA for bf16/fp16; on CPU/MPS stay in fp32
if model.device.type == "cuda":
with torch.autocast(device_type="cuda", dtype=model.dtype if model.dtype.is_floating_point else torch.bfloat16):
embeddings_doc = model(**batch_doc)
else:
embeddings_doc = model(**batch_doc)
doc_vecs.extend(list(torch.unbind(embeddings_doc.to("cpu"))))
return doc_vecs
def _embed_queries(model, processor, queries: List[str]) -> List[Any]:
import torch
from colpali_engine.utils.torch_utils import ListDataset
from torch.utils.data import DataLoader
model.eval()
dataloader = DataLoader(
dataset=ListDataset[str](queries),
batch_size=1,
shuffle=False,
collate_fn=lambda x: processor.process_queries(x),
)
q_vecs: List[Any] = []
for batch_query in dataloader:
with torch.no_grad():
batch_query = {k: v.to(model.device) for k, v in batch_query.items()}
if model.device.type == "cuda":
with torch.autocast(device_type="cuda", dtype=model.dtype if model.dtype.is_floating_point else torch.bfloat16):
embeddings_query = model(**batch_query)
else:
embeddings_query = model(**batch_query)
q_vecs.extend(list(torch.unbind(embeddings_query.to("cpu"))))
return q_vecs
def _build_index(index_path: str, doc_vecs: List[Any], filepaths: List[str]) -> LeannMultiVector:
dim = int(doc_vecs[0].shape[-1])
retriever = LeannMultiVector(index_path=index_path, dim=dim)
retriever.create_collection()
for i, vec in enumerate(doc_vecs):
data = {
"colbert_vecs": vec.float().numpy(),
"doc_id": i,
"filepath": filepaths[i],
}
retriever.insert(data)
retriever.create_index()
return retriever
def _load_retriever_if_index_exists(index_path: str, dim: int) -> Optional[LeannMultiVector]:
index_base = Path(index_path)
# Rough heuristic: index dir exists AND meta+labels files exist
meta = index_base.parent / f"{index_base.name}.meta.json"
labels = index_base.parent / f"{index_base.name}.labels.json"
if index_base.exists() and meta.exists() and labels.exists():
return LeannMultiVector(index_path=index_path, dim=dim)
return None
def _generate_similarity_map(
model,
processor,
image: Image.Image,
query: str,
token_idx: Optional[int] = None,
output_path: Optional[str] = None,
) -> Tuple[int, float]:
import torch
from colpali_engine.interpretability import (
get_similarity_maps_from_embeddings,
plot_similarity_map,
)
batch_images = processor.process_images([image]).to(model.device)
batch_queries = processor.process_queries([query]).to(model.device)
with torch.no_grad():
image_embeddings = model.forward(**batch_images)
query_embeddings = model.forward(**batch_queries)
n_patches = processor.get_n_patches(
image_size=image.size,
spatial_merge_size=getattr(model, "spatial_merge_size", None),
)
image_mask = processor.get_image_mask(batch_images)
batched_similarity_maps = get_similarity_maps_from_embeddings(
image_embeddings=image_embeddings,
query_embeddings=query_embeddings,
n_patches=n_patches,
image_mask=image_mask,
)
similarity_maps = batched_similarity_maps[0]
# Determine token index if not provided: choose the token with highest max score
if token_idx is None:
per_token_max = similarity_maps.view(similarity_maps.shape[0], -1).max(dim=1).values
token_idx = int(per_token_max.argmax().item())
max_sim_score = similarity_maps[token_idx, :, :].max().item()
if output_path:
import matplotlib.pyplot as plt
fig, ax = plot_similarity_map(
image=image,
similarity_map=similarity_maps[token_idx],
figsize=(14, 14),
show_colorbar=False,
)
ax.set_title(f"Token #{token_idx}. MaxSim score: {max_sim_score:.2f}", fontsize=12)
os.makedirs(os.path.dirname(output_path), exist_ok=True)
plt.savefig(output_path, bbox_inches="tight")
plt.close(fig)
return token_idx, float(max_sim_score)
class QwenVL:
def __init__(self, device: str):
from transformers.utils.import_utils import is_flash_attn_2_available
from transformers import Qwen2_5_VLForConditionalGeneration, AutoProcessor
attn_implementation = "flash_attention_2" if is_flash_attn_2_available() else "eager"
self.model = Qwen2_5_VLForConditionalGeneration.from_pretrained(
"Qwen/Qwen2.5-VL-3B-Instruct",
torch_dtype="auto",
device_map=device,
attn_implementation=attn_implementation,
)
min_pixels = 256 * 28 * 28
max_pixels = 1280 * 28 * 28
self.processor = AutoProcessor.from_pretrained(
"Qwen/Qwen2.5-VL-3B-Instruct", min_pixels=min_pixels, max_pixels=max_pixels
)
def answer(self, query: str, images: List[Image.Image], max_new_tokens: int = 128) -> str:
from qwen_vl_utils import process_vision_info
import base64
from io import BytesIO
content = []
for img in images:
buffer = BytesIO()
img.save(buffer, format="jpeg")
img_base64 = base64.b64encode(buffer.getvalue()).decode("utf-8")
content.append({"type": "image", "image": f"data:image;base64,{img_base64}"})
content.append({"type": "text", "text": query})
messages = [{"role": "user", "content": content}]
text = self.processor.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
image_inputs, video_inputs = process_vision_info(messages)
inputs = self.processor(text=[text], images=image_inputs, videos=video_inputs, padding=True, return_tensors="pt")
inputs = inputs.to(self.model.device)
generated_ids = self.model.generate(**inputs, max_new_tokens=max_new_tokens)
generated_ids_trimmed = [out_ids[len(in_ids) :] for in_ids, out_ids in zip(inputs.input_ids, generated_ids)]
return self.processor.batch_decode(
generated_ids_trimmed, skip_special_tokens=True, clean_up_tokenization_spaces=False
)[0]
#%%
# Step 1: Prepare data
if USE_HF_DATASET:
from datasets import load_dataset
dataset = load_dataset(DATASET_NAME, split=DATASET_SPLIT)
N = len(dataset) if MAX_DOCS is None else min(MAX_DOCS, len(dataset))
filepaths: List[str] = []
images: List[Image.Image] = []
for i in tqdm(range(N), desc="Loading dataset"):
p = dataset[i]
# Compose a descriptive identifier for printing later
identifier = (
f"arXiv:{p['paper_arxiv_id']}|title:{p['paper_title']}|page:{int(p['page_number'])}|id:{p['page_id']}"
)
filepaths.append(identifier)
images.append(p["page_image"]) # PIL Image
else:
_maybe_convert_pdf_to_images(PDF, PAGES_DIR)
filepaths, images = _load_images_from_dir(PAGES_DIR)
if not images:
raise RuntimeError(f"No images found in {PAGES_DIR}. Provide PDF path in PDF variable or ensure images exist.")
#%%
# Step 2: Load model and processor
model_name, model, processor, device_str, device, dtype = _load_colvision(MODEL)
print(f"Using model={model_name}, device={device_str}, dtype={dtype}")
#%%
#%%
# Step 3: Build or load index
retriever: Optional[LeannMultiVector] = None
if not REBUILD_INDEX:
try:
one_vec = _embed_images(model, processor, [images[0]])[0]
retriever = _load_retriever_if_index_exists(INDEX_PATH, dim=int(one_vec.shape[-1]))
except Exception:
retriever = None
if retriever is None:
doc_vecs = _embed_images(model, processor, images)
retriever = _build_index(INDEX_PATH, doc_vecs, filepaths)
#%%
# Step 4: Embed query and search
q_vec = _embed_queries(model, processor, [QUERY])[0]
results = retriever.search(q_vec.float().numpy(), topk=TOPK, first_stage_k=FIRST_STAGE_K)
if not results:
print("No results found.")
else:
print(f'Top {len(results)} results for query: "{QUERY}"')
top_images: List[Image.Image] = []
for rank, (score, doc_id) in enumerate(results, start=1):
path = filepaths[doc_id]
# For HF dataset, path is a descriptive identifier, not a real file path
print(f"{rank}) MaxSim: {score:.4f}, Page: {path}")
top_images.append(images[doc_id])
if SAVE_TOP_IMAGE:
from pathlib import Path as _Path
base = _Path(SAVE_TOP_IMAGE)
base.parent.mkdir(parents=True, exist_ok=True)
for rank, img in enumerate(top_images[: TOPK], start=1):
if base.suffix:
out_path = base.parent / f"{base.stem}_rank{rank}{base.suffix}"
else:
out_path = base / f"retrieved_page_rank{rank}.png"
img.save(str(out_path))
print(f"Saved retrieved page (rank {rank}) to: {out_path}")
#%%
# Step 5: Similarity maps for top-K results
if results and SIMILARITY_MAP:
token_idx = None if SIM_TOKEN_IDX < 0 else int(SIM_TOKEN_IDX)
from pathlib import Path as _Path
output_base = _Path(SIM_OUTPUT) if SIM_OUTPUT else None
for rank, img in enumerate(top_images[: TOPK], start=1):
if output_base:
if output_base.suffix:
out_dir = output_base.parent
out_name = f"{output_base.stem}_rank{rank}{output_base.suffix}"
out_path = str(out_dir / out_name)
else:
out_dir = output_base
out_dir.mkdir(parents=True, exist_ok=True)
out_path = str(out_dir / f"similarity_map_rank{rank}.png")
else:
out_path = None
chosen_idx, max_sim = _generate_similarity_map(
model=model,
processor=processor,
image=img,
query=QUERY,
token_idx=token_idx,
output_path=out_path,
)
if out_path:
print(f"Saved similarity map for rank {rank}, token #{chosen_idx} (max={max_sim:.2f}) to: {out_path}")
else:
print(f"Computed similarity map for rank {rank}, token #{chosen_idx} (max={max_sim:.2f})")
#%%
# Step 6: Optional answer generation
if results and ANSWER:
qwen = QwenVL(device=device_str)
response = qwen.answer(QUERY, top_images[: TOPK], max_new_tokens=MAX_NEW_TOKENS)
print("\nAnswer:")
print(response)