app.py

import os

os.system('pip install pip --upgrade')
os.system('pip install -q git+https://github.com/huggingface/transformers.git')


os.system("pip install pyyaml==5.1")
# workaround: install old version of pytorch since detectron2 hasn't released packages for pytorch 1.9 (issue: https://github.com/facebookresearch/detectron2/issues/3158)
os.system(
    "pip install torch==1.8.0+cu101 torchvision==0.9.0+cu101 -f https://download.pytorch.org/whl/torch_stable.html"
)

# install detectron2 that matches pytorch 1.8
# See https://detectron2.readthedocs.io/tutorials/install.html for instructions
os.system(
    "pip install -q detectron2 -f https://dl.fbaipublicfiles.com/detectron2/wheels/cu101/torch1.8/index.html"
)

## install PyTesseract
os.system("pip install -q pytesseract")

import gradio as gr
import numpy as np
from transformers import AutoModelForTokenClassification
from datasets.features import ClassLabel
from transformers import AutoProcessor
from datasets import Features, Sequence, ClassLabel, Value, Array2D, Array3D
import torch
from datasets import load_metric
from transformers import LayoutLMv3ForTokenClassification
from transformers.data.data_collator import default_data_collator


from transformers import AutoModelForTokenClassification
from datasets import load_dataset
from PIL import Image, ImageDraw, ImageFont


processor = AutoProcessor.from_pretrained("jinhybr/OCR-LayoutLMv3-Invoice", apply_ocr=True)
model = AutoModelForTokenClassification.from_pretrained("jinhybr/OCR-LayoutLMv3-Invoice")



# load image example
dataset = load_dataset("jinhybr/WildReceipt", split="test")
Image.open(dataset[1]["image_path"]).convert("RGB").save("example1.png")
Image.open(dataset[3]["image_path"]).convert("RGB").save("example2.png")
Image.open(dataset[25]["image_path"]).convert("RGB").save("example3.png")
# define id2label, label2color
labels = dataset.features['ner_tags'].feature.names
id2label = {v: k for v, k in enumerate(labels)}
label2color = {
    "Date_key": 'red',
    "Date_value": 'green',
    "Ignore": 'orange',
    "Others": 'orange',
    "Prod_item_key": 'red',
    "Prod_item_value": 'green',
    "Prod_price_key": 'red',
    "Prod_price_value": 'green',
    "Prod_quantity_key": 'red',
    "Prod_quantity_value": 'green',
    "Store_addr_key": 'red',
    "Store_addr_value": 'green',
    "Store_name_key": 'red',
    "Store_name_value": 'green',
    "Subtotal_key": 'red',
    "Subtotal_value": 'green',
    "Tax_key": 'red',
    "Tax_value": 'green',
    "Tel_key": 'red',
    "Tel_value": 'green',
    "Time_key": 'red',
    "Time_value": 'green',
    "Tips_key": 'red',
    "Tips_value": 'green',
    "Total_key": 'red',
    "Total_value": 'blue'
  }

def unnormalize_box(bbox, width, height):
     return [
         width * (bbox[0] / 1000),
         height * (bbox[1] / 1000),
         width * (bbox[2] / 1000),
         height * (bbox[3] / 1000),
     ]


def iob_to_label(label):
    return label



def process_image(image):

    print(type(image))
    width, height = image.size

    # encode
    encoding = processor(image, truncation=True, return_offsets_mapping=True, return_tensors="pt")
    offset_mapping = encoding.pop('offset_mapping')

    # forward pass
    outputs = model(**encoding)

    # get predictions
    predictions = outputs.logits.argmax(-1).squeeze().tolist()
    token_boxes = encoding.bbox.squeeze().tolist()

    # only keep non-subword predictions
    is_subword = np.array(offset_mapping.squeeze().tolist())[:,0] != 0
    true_predictions = [id2label[pred] for idx, pred in enumerate(predictions) if not is_subword[idx]]
    true_boxes = [unnormalize_box(box, width, height) for idx, box in enumerate(token_boxes) if not is_subword[idx]]

    # draw predictions over the image
    draw = ImageDraw.Draw(image)
    font = ImageFont.load_default()
    for prediction, box in zip(true_predictions, true_boxes):
        predicted_label = iob_to_label(prediction)
        draw.rectangle(box, outline=label2color[predicted_label])
        draw.text((box[0]+10, box[1]-10), text=predicted_label, fill=label2color[predicted_label], font=font)
    
    return image


title = "OCR Invoice - Information Extraction - LayoutLMv3"
description = "Fine-tuned Microsoft's LayoutLMv3 on WildReceipt Dataset to parse Invoice OCR document. To use it, simply upload an image or use the example image below. Results will show up in a few seconds."

article="<b>References</b><br>[1] Y. Xu et al., “LayoutLMv3: Pre-training for Document AI with Unified Text and Image Masking.” 2022. <a href='https://arxiv.org/abs/2204.08387'>Paper Link</a><br>[2]  <a href='https://github.com/NielsRogge/Transformers-Tutorials/tree/master/LayoutLMv3'>LayoutLMv3 training and inference</a><br>[3] Hongbin Sun, Zhanghui Kuang, Xiaoyu Yue, Chenhao Lin, and Wayne Zhang. 2021. Spatial Dual-Modality Graph Reasoning for Key Information Extraction. arXiv. DOI:https://doi.org/10.48550/ARXIV.2103.14470  <a href='https://doi.org/10.48550/ARXIV.2103.14470'>Paper Link</a>" 

examples =[['example1.png'],['example2.png'],['example3.png'],['inv2.jpg']]

css = """.output_image, .input_image {height: 600px !important}"""

iface = gr.Interface(fn=process_image, 
                     inputs=gr.inputs.Image(type="pil"), 
                     outputs=gr.outputs.Image(type="pil", label="annotated image"),
                     title=title,
                     description=description,
                     article=article,
                     examples=examples,
                     css=css,
                     analytics_enabled = True, enable_queue=True)

iface.launch(inline=False, share=False, debug=True)