microsoft / dit-base

Document Image Transformer (base-sized model)

Document Image Transformer (DiT) model pre-trained on IIT-CDIP (Lewis et al., 2006), a dataset that includes 42 million document images. It was introduced in the paper DiT: Self-supervised Pre-training for Document Image Transformer by Li et al. and first released in this repository . Note that DiT is identical to the architecture of BEiT .

Disclaimer: The team releasing DiT did not write a model card for this model so this model card has been written by the Hugging Face team.

Model description

The Document Image Transformer (DiT) is a transformer encoder model (BERT-like) pre-trained on a large collection of images in a self-supervised fashion. The pre-training objective for the model is to predict visual tokens from the encoder of a discrete VAE (dVAE), based on masked patches.

Images are presented to the model as a sequence of fixed-size patches (resolution 16x16), which are linearly embedded. One also adds absolute position embeddings before feeding the sequence to the layers of the Transformer encoder.

By pre-training the model, it learns an inner representation of images that can then be used to extract features useful for downstream tasks: if you have a dataset of labeled document images for instance, you can train a standard classifier by placing a linear layer on top of the pre-trained encoder.

Intended uses & limitations

You can use the raw model for encoding document images into a vector space, but it's mostly meant to be fine-tuned on tasks like document image classification, table detection or document layout analysis. See the model hub to look for fine-tuned versions on a task that interests you.

How to use

Here is how to use this model in PyTorch:

from transformers import BeitImageProcessor, BeitForMaskedImageModeling
import torch
from PIL import Image

image = Image.open('path_to_your_document_image').convert('RGB')

processor = BeitImageProcessor.from_pretrained("microsoft/dit-base")
model = BeitForMaskedImageModeling.from_pretrained("microsoft/dit-base")

num_patches = (model.config.image_size // model.config.patch_size) ** 2
pixel_values = processor(images=image, return_tensors="pt").pixel_values
# create random boolean mask of shape (batch_size, num_patches)
bool_masked_pos = torch.randint(low=0, high=2, size=(1, num_patches)).bool()

outputs = model(pixel_values, bool_masked_pos=bool_masked_pos)
loss, logits = outputs.loss, outputs.logits

BibTeX entry and citation info

@article{Lewis2006BuildingAT,
  title={Building a test collection for complex document information processing},
  author={David D. Lewis and Gady Agam and Shlomo Engelson Argamon and Ophir Frieder and David A. Grossman and Jefferson Heard},
  journal={Proceedings of the 29th annual international ACM SIGIR conference on Research and development in information retrieval},
  year={2006}
}