PaddleOCR/ppstructure

PPStructure

PPStructure is an OCR toolkit for complex layout analysis. It can divide document data in the form of pictures into text, table, title, picture and list 5 types of areas, and extract the table area as excel

1. Quick start

install

install paddleocr

ref to paddleocr whl doc

install layoutparser

pip3 install -U premailer https://paddleocr.bj.bcebos.com/whl/layoutparser-0.0.0-py3-none-any.whl

1.2 Use

1.2.1 Use by command line

paddleocr --image_dir=../doc/table/1.png --type=structure

1.2.2 Use by code

import os
import cv2
from paddleocr import PPStructure,draw_structure_result,save_structure_res

table_engine = PPStructure(show_log=True)

save_folder = './output/table'
img_path = '../doc/table/1.png'
img = cv2.imread(img_path)
result = table_engine(img)
save_structure_res(result, save_folder,os.path.basename(img_path).split('.')[0])

for line in result:
    print(line)

from PIL import Image

font_path = '../doc/fonts/simfang.ttf'
image = Image.open(img_path).convert('RGB')
im_show = draw_structure_result(image, result,font_path=font_path)
im_show = Image.fromarray(im_show)
im_show.save('result.jpg')

1.2.3 返回结果说明

The return result of PPStructure is a list composed of a dict, an example is as follows

[
  {   'type': 'Text', 
      'bbox': [34, 432, 345, 462], 
      'res': ([[36.0, 437.0, 341.0, 437.0, 341.0, 446.0, 36.0, 447.0], [41.0, 454.0, 125.0, 453.0, 125.0, 459.0, 41.0, 460.0]], 
                [('Tigure-6. The performance of CNN and IPT models using difforen', 0.90060663), ('Tent  ', 0.465441)])
  }
]

The description of each field in dict is as follows

Parameter	Description
type	Type of image area
bbox	The coordinates of the image area in the original image, respectively [left upper x, left upper y, right bottom x, right bottom y]
res	OCR or table recognition result of image area。 Table: HTML string of the table; OCR: A tuple containing the detection coordinates and recognition results of each single line of text

1.2.4 Parameter Description：

Parameter	Description	Default value
output	The path where excel and recognition results are saved	./output/table
table_max_len	The long side of the image is resized in table structure model	488
table_model_dir	inference model path of table structure model	None
table_char_type	dict path of table structure model	../ppocr/utils/dict/table_structure_dict.tx

Most of the parameters are consistent with the paddleocr whl package, see doc of whl

After running, each image will have a directory with the same name under the directory specified in the output field. Each table in the picture will be stored as an excel, and the excel file name will be the coordinates of the table in the image.

2. PPStructure Pipeline

the process is as follows

In PPStructure, the image will be analyzed by layoutparser first. In the layout analysis, the area in the image will be classified, including text, title, image, list and table 5 categories. For the first 4 types of areas, directly use the PP-OCR to complete the text detection and recognition. The table area will be converted to an excel file of the same table style via Table OCR.

2.1 LayoutParser

Layout analysis divides the document data into regions, including the use of Python scripts for layout analysis tools, extraction of special category detection boxes, performance indicators, and custom training layout analysis models. For details, please refer to document.

2.2 Table OCR

Table OCR converts table image into excel documents, which include the detection and recognition of table text and the prediction of table structure and cell coordinates. For detailed, please refer to document

3. Predictive by inference engine

Use the following commands to complete the inference.

python3 table/predict_system.py --det_model_dir=path/to/det_model_dir --rec_model_dir=path/to/rec_model_dir --table_model_dir=path/to/table_model_dir --image_dir=../doc/table/1.png --rec_char_dict_path=../ppocr/utils/dict/table_dict.txt --table_char_dict_path=../ppocr/utils/dict/table_structure_dict.txt --rec_char_type=EN --det_limit_side_len=736 --det_limit_type=min --output=../output/table --vis_font_path=../doc/fonts/simfang.ttf

After running, each image will have a directory with the same name under the directory specified in the output field. Each table in the picture will be stored as an excel, and the excel file name will be the coordinates of the table in the image.

Model List

model name	description	config	model size	download
en_ppocr_mobile_v2.0_table_det	Text detection in English table scene	ch_det_mv3_db_v2.0.yml	4.7M	inference model
en_ppocr_mobile_v2.0_table_rec	Text recognition in English table scene	rec_chinese_lite_train_v2.0.yml	6.9M	inference model
en_ppocr_mobile_v2.0_table_structure	Table structure prediction for English table scenarios	table_mv3.yml	18.6M	inference model