Prodigy-PDF for PDF annotation and OCR

2023-10-24 · Source: Explosion · Developer tools and consulting for AI, Machine Learning and NLP - Explosion.ai · Field: Technology & Digital — Artificial Intelligence & Machine Learning, Data Science & Analytics · Depth: Intermediate, medium

Summary

Prodigy-PDF is a utility plugin for Prodigy designed to streamline annotation tasks on PDF files. It features recipes like "PDF image manual", which converts PDFs into images, enabling users to manually annotate elements such as titles, paragraphs, and figures within an intuitive interface that supports zooming. Once annotations are created, the "PDF OCR correct" recipe can be employed to process specific annotated segments, leveraging libraries like PyTesseract to convert image-based text into editable strings. This recipe also includes a "fold dashes" setting, which merges hyphenated words across lines into a single string, providing a more accurate textual representation for downstream use cases. The plugin aims to offer pragmatic tools for PDF-related data extraction and preparation.

Key takeaway

For Data Scientists or AI Engineers working with unstructured PDF data, Prodigy-PDF provides a robust solution for preparing training datasets. You can efficiently annotate document layouts and then accurately extract text from specific regions, significantly reducing manual data preparation time. Consider using the "fold dashes" setting in the OCR step to ensure cleaner text output, which is crucial for downstream NLP model training. This workflow streamlines the creation of high-quality, labeled PDF datasets.

Key insights

Prodigy-PDF offers a two-step workflow for annotating PDF content and extracting text via OCR, enhancing data preparation.

Principles

• PDF content can be treated as images for flexible annotation.
• OCR accuracy benefits from high-contrast, upsampled image segments.
• Text normalization (e.g., dash folding) improves OCR output utility.

Method

1. Use "PDF image manual" to annotate titles, paragraphs, and figures in PDFs. 2. Apply "PDF OCR correct" to convert annotated segments into text, optionally using "fold dashes".

In practice

• Annotate academic articles for structure and content.
• Extract clean text from scanned documents.
• Prepare PDF data for machine learning tasks.

Topics

• Prodigy-PDF
• PDF Annotation
• Optical Character Recognition
• Data Labeling
• PyTesseract
• Document AI

Best for: Machine Learning Engineer, AI Engineer, Data Scientist

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Editorial summary, takeaway, and curation by AIssential. Original article published by Explosion · Developer tools and consulting for AI, Machine Learning and NLP - Explosion.ai.