Text Detection and OCR with Amazon Rekognition API

2022-03-21 · Source: Adrian Rosebrock, Author at PyImageSearch · Field: Technology & Digital — Artificial Intelligence & Machine Learning, Cloud Computing & IT Infrastructure · Depth: Intermediate, long

Summary

This tutorial details how to perform text detection and Optical Character Recognition (OCR) using the Amazon Rekognition API. It covers configuring a development environment, obtaining AWS Rekognition keys, and installing the `boto3` Python package for AWS API interaction. The core of the guide involves implementing a Python script that loads an image, packages it into an API request, sends it to Amazon Rekognition for OCR, and then retrieves and displays the results. The Amazon Rekognition API offers high accuracy, capable of OCR'ing text in complex, unconstrained conditions, and can return results grouped by either lines or individual words. The process involves scaling bounding box coordinates returned by the API (which are in the range [0, 1]) back to the original image dimensions for accurate visualization.

Key takeaway

For AI Engineers building robust text extraction systems, consider integrating Amazon Rekognition API for its high accuracy in diverse conditions. While it introduces network latency and cost, its ability to parse text at both line and word levels offers greater granularity than many local OCR engines. Prioritize this API for projects where accuracy is paramount and an internet connection is stable, especially if you're already within the AWS ecosystem.

Key insights

Amazon Rekognition API offers highly accurate cloud-based OCR, providing line or word-level text detection.

Principles

• Cloud OCR APIs offer superior accuracy over local engines like Tesseract.
• API-based models keep proprietary data and models secure.
• Bounding box coordinates from Rekognition are normalized [0,1].

Method

Connect to AWS Rekognition via `boto3`, send a binary image to `detect_text`, then process and visualize the returned text detections and scaled bounding box coordinates.

In practice

• Use `boto3` for Python integration with AWS Rekognition.
• Configure `aws_config.py` with access keys and region.
• Scale normalized bounding box coordinates for display.

Topics

• Amazon Rekognition API
• Optical Character Recognition
• Text Detection
• AWS boto3 SDK
• Cloud AI Services

Best for: Machine Learning Engineer, AI Engineer, Software Engineer

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Editorial summary, takeaway, and curation by AIssential. Original article published by Adrian Rosebrock, Author at PyImageSearch.