Postprocessing with Amazon Textract: Multi-page table handling

Amazon Textract is an artificial intelligence (ML) service that automatically extracts printed text, handwriting, and other information from scanned documents that exceeds simple optical character recognition (OCR) to recognize and draw out information from tables and kinds.
Presently, thousands of customers are using Amazon Textract to process different types of documents. Numerous include tables across one or several pages, such as bank statements and monetary reports.
Lots of designers expressed interest in combining Amazon Textract actions where tables exist across multiple pages. This post shows how you can utilize the amazon-textract-response-parser energy to achieve this and highlights a few techniques to enhance the procedure.
Solution summary
A series of recognitions and steps are needed to identify the linkage across pages properly when tables span several pages.
These include evaluating the table structure resemblances across pages (columns, headers, margins) and identifying if any extra contents like headers or footers exist that may rationally break the tables. These logical actions are separated into 2 major groups (page context and table structure), and you can adjust and optimize each logical step according to your usage case.
This service runs these jobs in series and only combines the outcomes when all checks are finished and passed. The following diagram shows the option workflow.

Execute the service
The Amazon Textract reaction parser library allows us to easily parse the Amazon Textract JSON action and supplies constructs to work with different parts of the document effectively. This post focuses on the merge/link tables feature.

Install the libraries with the following code:

! pip set up amazon-textract-response-parser
! pip install amazon-textract-helper

The postprocessing action to determine associated tables and merge them belongs to the trp.trp2 library, which you should import into your notebook:

import trp.trp2 as t2
from trp.t _ pipeline import pipeline_merge_tables
from textractcaller.t _ call import call_textract, Textract_Features
from trp.trp2 import TDocument, TDocumentSchema
from trp.t _ tables import MergeOptions, HeaderFooterType

Next, call Amazon Textract to process the file:

table_ids_merge_list = [] ordered_doc = order_blocks_by_geo( t_document).
trp_doc = Document( TDocumentSchema(). dump( ordered_doc)).
for current_page in trp_doc. pages:.
for table in current_page. tables:.
# Provide your custom-made reasoning here to identify which tableids should merge to one table.
# if( customized reasoning).
# table_ids_merge_list. append(>> tableid1, tableid2, tableid3, … etc).
return table_ids_merge_list.

Pipeline_merge_tables takes a merge option criterion that can be either.MERGE or.LINK.
MergeOptions.MERGE integrates the tables and makes them appear as one for postprocessing, with the drawback that the geometry info is no longer in the proper location due to the fact that you now have cells and tables from subsequent pages moved to the page with the first part of the table.
MergeOptions.LINK preserves the geometric structure and enhances the table details with links between the table components.
The following image represents a sample PDF file with a table that covers over two pages.

Define a custom table merge validation function.
The supplied postprocessing API works for the majority of use cases; nevertheless, based upon your specific use case, you can define a customized merge function to improve its accuracy.
This custom-made function is passed to the CustomTableDetectionFunction parameter of the pipeline_merge_tables function to overwrite the existing reasoning of identifying the tables to merge. The following steps represent the existing reasoning.

Our existing implementation for the table detection function and pipeline_merge_tables function in our Amazon Textract response parser library is offered on GitHub. The customTableDetection function returns a list of lists (of strings), which is required by the merge_table or link_table functions (based on the MergeOptions parameter) called internally by the pipeline_merge_tables API.
Run sample code.
The Amazon Textract multi-page tables processing repository supplies sample code on how to use the combine tables feature and covers typical situations that you may come across in your documents. To try the sample code, you first release an Amazon SageMaker note pad circumstances with the code repository, then you can access the note pad to evaluate the code samples.
Introduce a SageMaker note pad circumstances with the code repository.
To launch a SageMaker notebook instance, finish the following steps:.

Gain access to the SageMaker note pad and evaluate the code samples.
You can access the note pad and review the code samples when the stack production is total.

About the Authors.
Mehran Najafi, PhD, is a Senior Solutions Architect for AWS focused on AI/ML services and architectures at scale.
Keith Mascarenhas is a Solutions Architect and deals with our small and medium sized customers in main Canada to assist them grow and achieve outcomes much faster with AWS. He is also passionate about artificial intelligence and belongs to the Amazon Computer Vision Hero program.
Yuan Jiang is a Sr Solutions Architect with a focus in artificial intelligence. Hes a member of the Amazon Computer Vision Hero program and the Amazon Machine Learning Technical Field Community.
Martin Schade is a Senior ML Product SA with the Amazon Textract group. He has more than 20 years of experience with internet-related innovations, engineering, and architecting solutions, and joined AWS in 2014. He has guided some of the largest AWS customers on the most scalable and efficient use of AWS services, and later on focused on AI/ML with a concentrate on computer system vision. He is currently obsessed with drawing out information from documents.

On the Outputs tab of the stack, pick the link representing the worth of the NotebookInstanceName secret.
Select Open Jupyter.
Go to the house page of your Jupyter note pad and browse to the amazon-textract-multipage-tables-processing directory.
Open the Jupyter notebook inside this directory site and the sample code provided.

The following shows the Amazon Textract action without table merge postprocessing (left) and the action with table merge postprocessing (right).

t_document = pipeline_merge_tables( t_document, MergeOptions.MERGE, CustomTableDetectionFunction, HeaderFooterType.NORMAL).

On the evaluation page, acknowledge the IAM resource creation and select Create stack.

Choose Next.
For Specify Stack Name, go into a stack name.
Select Next.
Choose Next.

You come to the Create Stack page on the Specify Template action.

Choose the following link to release an AWS CloudFormation design template that deploys a SageMaker notebook circumstances in addition to the sample code repository:.

textract_json = call_textract( input_document= s3_uri_of_documents, features= [Textract_Features. TABLES], boto3_textract_client = textract_client).

Load the action JSON into a file and run the pipeline. The footer and header heights are configurable by the user. There are 3 default values can be utilized for HeaderFooterType: None, Narrow, and Normal.

Conclusion.
This post demonstrated how to utilize the Amazon Textract action parser element to recognize and combine tables that span several pages. You strolled through generic checks that you can utilize to identify a multi-page table, found out how to construct your own custom-made function, and examined the two options to merge tables in the Amazon Textract action JSON.
We would love to hear about it if this post assists you or inspires you to resolve a problem! The code for this service is available on the GitHub repo for you to use and extend. Contributions are constantly welcome!

t_document: t2.TDocument = t2.TDocumentSchema(). load( textract_json).
t_document = pipeline_merge_tables( t_document, MergeOptions.MERGE, None, HeaderFooterType.NONE).

If you have a different requirement, you can pass your own custom table detection function to the pipeline_merge_tables API as follows:.

Check in to the AWS Management Console with your AWS Identity and Access Management (IAM) user name and password.

MergeOptions.LINK maintains the geometric structure and improves the table details with links in between the table aspects. Check if there are any line items in between the very first and 2nd table except in the footer and header area. If there are any line products, tables are thought about different tables.
Verify that the 2 tables have the same left and right margin. An accuracy percentage criterion can be passed to allow for some degree of error (for example, if the pages are scanned from papers, ensuing tables on various pages may have different weights).

Confirm context in between tables. If there are any line products in between the first and 2nd table other than in the footer and header area, examine. If there are any line items, tables are considered separate tables.
Compare the column numbers. If the 2 tables dont have the very same variety of columns, this is an indicator of separate logical tables.
Compare the headers. If the two tables have the specific same columns (same cell number and cell labels), this is a really strong indication of the exact same sensible table.
Compare table dimensions. Confirm that the two tables have the very same left and ideal margin. A precision portion parameter can be passed to permit some degree of error (for example, if the pages are scanned from documents, ensuing tables on different pages may have different weights).

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