Image-Text-to-Text
sentence-transformers
Safetensors
Transformers
qwen2_vl
Qwen2-VL
conversational
vdr-2b-multi-v1 / README.md
marco's picture
Update README.md
6f270fc verified
|
raw
history blame
9.48 kB
metadata
license: apache-2.0
language:
  - en
  - it
  - fr
  - de
  - es
base_model:
  - MrLight/dse-qwen2-2b-mrl-v1
tags:
  - transformers
  - Qwen2-VL

vdr-2b-multi-v1

vdr-2b-multi-v1 is a multilingual embedding model designed for visual document retrieval across multiple languages and domains. This model is designed to encode document page screenshots into dense single-vector representations, this will effectively allow to search and query visually rich multilingual documents without the need for any OCR, data extraction pipelines, chunking...

  • Trained on ๐Ÿ‡ฎ๐Ÿ‡น Italian, ๐Ÿ‡ช๐Ÿ‡ธ Spanish, ๐Ÿ‡ฌ๐Ÿ‡ง English, ๐Ÿ‡ซ๐Ÿ‡ท French and ๐Ÿ‡ฉ๐Ÿ‡ช German: together they form a new large, open-source, multilingual training dataset of 500k high-quality samples.

  • Cross-lingual Retrieval: substantially better on real-world scenarios. For example, this allows for searching german documents with italian queries.

  • Matryoshka Representation Learning: You can reduce the vectors size 3x and still keep 98% of the embeddings quality.

To know more about the model, read the announcement blogpost.

Usage

Initialize model and processor

from transformers import AutoProcessor, Qwen2VLForConditionalGeneration
from PIL import Image
import torch
import math

# more pixels -> better embeddings -> more VRAM -> slower inference
# From my experience, 768 image patches is the right spot for compute efficient embeddings.
max_pixels = 768 * 28 * 28
min_pixels = 1 * 28 * 28

# Load the embedding model and processor
model = Qwen2VLForConditionalGeneration.from_pretrained(
    'llamaindex/vdr-2b-multi-v1',
    attn_implementation="flash_attention_2",
    torch_dtype=torch.bfloat16,
    device_map="cuda:0"
).eval()

processor = AutoProcessor.from_pretrained(
    'llamaindex/vdr-2b-multi-v1',
    min_pixels=min_pixels,
    max_pixels=max_pixels
)

model.padding_side = "left"
processor.tokenizer.padding_side = "left"

document_prompt = "<|im_start|>system\nYou are a helpful assistant.<|im_end|>\n<|im_start|>user\n<|vision_start|><|image_pad|><|vision_end|>What is shown in this image?<|im_end|>\n<|endoftext|>"

query_prompt = "<|im_start|>system\nYou are a helpful assistant.<|im_end|>\n<|im_start|>user\n<|vision_start|><|image_pad|><|vision_end|>Query: %s<|im_end|>\n<|endoftext|>"

Encode queries

def encode_queries(queries: list[str], dimension: int) -> torch.Tensor:
    """
    Encode a list of queries into a tensor of embeddings.

    Args:
        queries: A list of strings, each representing a query.
        dimension: The desired dimension of the output embeddings.

    Returns:
        A tensor of shape (num_queries, dimension) containing the encoded queries.
    """

    dummy_image = Image.new('RGB', (56, 56))
    inputs = processor(
        text=[query_prompt % x for x in queries],
        images=[dummy_image for _ in queries],
        videos=None,
        padding='longest',
        return_tensors='pt'
    ).to('cuda:0')

    cache_position = torch.arange(0, len(queries))
    inputs = model.prepare_inputs_for_generation(
        **inputs, cache_position=cache_position, use_cache=False)

    with torch.no_grad():
        output = self.model(
            **inputs,
            return_dict=True,
            output_hidden_states=True
        )

    embeddings = output.hidden_states[-1][:, -1]
    return torch.nn.functional.normalize(embeddings[:, :dimension], p=2, dim=-1)

Encode documents

def round_by_factor(number: float, factor: int) -> int:
    return round(number / factor) * factor

def ceil_by_factor(number: float, factor: int) -> int:
    return math.ceil(number / factor) * factor

def floor_by_factor(number: float, factor: int) -> int:
    return math.floor(number / factor) * factor

def smart_resize(height: int, width: int) -> tuple[int, int]:
    h_bar = max(28, round_by_factor(height, 28))
    w_bar = max(28, round_by_factor(width, 28))
    if h_bar * w_bar > max_pixels:
        beta = math.sqrt((height * width) / max_pixels)
        h_bar = floor_by_factor(height / beta, 28)
        w_bar = floor_by_factor(width / beta, 28)
    elif h_bar * w_bar < min_pixels:
        beta = math.sqrt(min_pixels / (height * width))
        h_bar = ceil_by_factor(height * beta, 28)
        w_bar = ceil_by_factor(width * beta, 28)
    return w_bar, h_bar

def resize(image: Image.Image):
    new_size = smart_resize(image.height, image.width)
    return image.resize(new_size)

def encode_documents(documents: list[Image.Image], dimension: int):
    """
    Encode a list of images into a tensor of embeddings.

    Args:
        documents: A list of PIL Image objects.
        dimension: The desired dimension of the output embeddings.

    Returns:
        A tensor of shape (num_documents, dimension) containing the encoded images.
    """
    
    inputs = processor(
        text=[document_prompt] * len(documents),
        images=[resize(x) for x in documents],
        videos=None,
        padding='longest',
        return_tensors='pt'
    ).to('cuda:0')

    cache_position = torch.arange(0, len(queries))
    inputs = model.prepare_inputs_for_generation(
        **inputs, cache_position=cache_position, use_cache=False)

    with torch.no_grad():
        output = self.model(
            **inputs,
            return_dict=True,
            output_hidden_states=True
        )
    
    embeddings = output.hidden_states[-1][:, -1]
    return torch.nn.functional.normalize(embeddings[:, :dimension], p=2, dim=-1)

Training

The model is based on MrLight/dse-qwen2-2b-mrl-v1 and it was trained on the new vdr-multilingual-train dataset that consinsists of 500k high quality, multilingual query image pairs. It was trained for 1 epoch using the DSE approach, with a batch size of 128 and hard-mined negatives.

Results

The model has been evaluated on the Vidore benchmark and on custom-built evaluation sets that allow testing its multilingual capabilities on text-only, visual-only and mixed page screenshots. The evaluation dataset is publicly available here on HuggingFace.

All evaluations are performed by calculating NDCG@5 scores using 1536 dimensions vectors and an image resolution that can be represented with maximum 768 tokens.

Avg Italian (text) Italian (visual) Italian (mix)
dse-qwen2-2b-mrl-v1 95.1 95.1 94 96.2
vdr-2b-multi-v1 97.0 96.4 96.3 98.4
+2%
Avg French (text) French (visual) French (mix)
dse-qwen2-2b-mrl-v1 93.5 94.7 90.8 95.1
vdr-2b-multi-v1 95.6 95.6 93.3 97.9
+2.2%
Avg Spanish (text) Spanish (visual) Spanish (mix)
dse-qwen2-2b-mrl-v1 96.7 97.2 94.7 98.2
vdr-2b-multi-v1 98.1 98.3 96.9 99.1
+1.4%
Avg German (text) German (visual) German (mix)
dse-qwen2-2b-mrl-v1 93.0 93.4 90 95.5
vdr-2b-multi-v1 96.2 94.8 95.7 98.1
+3.4%
Avg English (text) English (visual) English (mix)
dse-qwen2-2b-mrl-v1 98.0 98.3 98.5 97.1
vdr-2b-multi-v1 98.1 97.9 99.1 97.3
+0.1%
Avg shiftproject government healthcare energy ai docvqa arxivqa tatdqa infovqa tabfquad
dse-qwen2-2b-mrl-v1 83.6 79.8 95.7 96.9 92 98.2 56.3 85.2 53.9 87.5 90.3
vdr-2b-multi-v1 84.0 82.4 95.5 96.5 91.2 98.5 58.5 84.7 53.6 87.1 92.2