AWS Transactional Document Digitization

AWS workflow for digitizing transactional documents with Amazon Textract and a human-review loop with Amazon Augmented Artificial Intelligence (A2I). Deployed using CDK.

Architecture

Basic Usage Workflow:

• Put a scanned tabular transactional PDF document in s3 at s3://tdd-<git-branch>-store-resource-<account-number>-<region>/acquire/
• This action triggers the tdd-<git-branch>-state-pipeline step function which will:
  • Analyze the PDF document with Textract with table extraction
  • Convert the textract table extractions to a simplified JSON format
  • Apply business rules to the simplified JSON format (currently a pass-through operation)
  • Send the PDF document and simplified JSON to A2I for human review of low-confidence values
  • Once human review is complete, convert output to a spreadsheet that has one sheet per table found in the original PDF document
• Monitor document status in DynamoDB in the tdd-<git-branch>-table-pipeline table
• Once your document has reached the Status Augment#Waiting, it's time to perform human review using the worker portal (descrbied below)
• After human review, find the final Excel spreadsheet in s3://tdd-<git-branch>-store-resource-<account-number>-<region>/acquire/catalog

Human Review Annotation Interface

This interface allows annotators to review all tables found in a scanned pdf document and perform the following actions:

• Classify each table table with a type
• Classify each table column header with a type
• Make cell-level text corrections to any table cell value.

Installation

SageMaker Private Workforce Setup

This application uses SageMaker labeling workforces to manage workers and distribute tasks. Create a private workforce, workers team called primary and quality, and assign yourself to both teams using these instructions: https://docs.aws.amazon.com/sagemaker/latest/dg/sms-workforce-create-private-console.html#create-workforce-sm-console

Once you’ve added yourself to the private workforce teams and confirmed your email, take note of the worker portal URL from the AWS Console by:

• Navigate to SageMaker
• Navigate to Ground Truth → Labeling workforces
• Click the Private tab
• Note the URL Labeling portal sign-in - you will log in here to perform A2I human reviews.

Application Deployment with CDK

Deploying this application to your AWS account will create various S3 buckets, Lambda functions, IAM policies, an SQS queue, and a step function.

Pre-Requisites

1. Install CDK Toolkit

• npm install -g aws-cdk

2. Install Docker, and Run

• For Mac : https://docs.docker.com/docker-for-mac/install
• For Win : https://docs.docker.com/docker-for-windows/install

Instruction to Deploy Application to AWS Cloud

1. cd TabularDocumentDigitization
2. python3 -m venv .venv --prompt tdd - Create virtual environment
3. source .venv/bin/activate - Enter virtual environment
4. pip install . - Install dependencies in virtual environment
5. cdk bootstrap - Only run this once per account setup
6. edit cdk.json, set your work team name - Pre-create the workteam via aws console, and make sure to match workteam name in same region/account
7. cdk deploy --all - Deploy application

Deployment Prefix

To deploy the same application multiple times to the same account, either change your current git branch and redeploy or set the DEPLOY env variable.

Ex:

DEPLOY="development" cdk deploy --all
DEPLOY="production" cdk deploy --all

This will deploy two copies of the application under different prefixes.

Running Lambda Unit Tests

Install pytest dependencies

pip install pytest coverage pytest-cov pytest-xdist pytest-env

Run lambda unit tests from the base project folder. Omit --looponfail to run the tests once instead of continuously.

PYTHONPATH=./source/lambdas/ pytest \
    tests/lambdas/ \
    --cov=source/lambdas/ \
    --cov-report term-missing \
    --looponfail