Earn 4,500 ($45.00)
Write a Tiny Web App to Read in a PDF Using PDF.js and Extract Annotation Images
Bounty Description
Overview
Create a tiny web application that allows users to upload PDF files, process them using PDF.js, and extract images from annotations within the PDFs. This bounty requires a solid understanding of the PDF format, the PDF.js library, and image processing in JavaScript.
Requirements
Allow users to upload a PDF file through a simple web interface
Use PDF.js to parse and render the PDF content
Identify and extract all images embedded within annotations in the PDF
Display the extracted images to the user
Provide a way to download individual images or all images as a zip file
Technical Details
PDF.js Integration:
Implement proper initialization and error handling for PDF.js
Handle PDF.js's asynchronous nature correctly
Work with PDF.js's document and page object model to access annotations
Annotation Processing:
Correctly identify different types of PDF annotations (stamps, ink, etc.)
Extract image data from relevant annotation objects
Convert PDF binary image data to standard web image formats (PNG/JPEG)
Preserve image metadata if possible (name, page number, coordinates)
User Interface:
Create a clean, minimal UI that's easy to understand
Show a preview of the uploaded PDF
Display extracted annotation images with relevant details
Implement responsive design for different screen sizes
Challenges to Overcome
Annotation Structure Complexity: PDF annotations vary widely in structure and implementation. You'll need to handle different annotation types and structures.
Binary Data Extraction: Extracting and processing binary image data from PDF objects requires careful handling of different formats and encodings.
PDF.js Limitations: PDF.js doesn't directly expose all annotation data in a simple format - you'll need to understand its internal structures.
Cross-Browser Compatibility: Ensure your solution works across modern browsers (Chrome, Firefox, Safari, Edge).
Performance Optimization: Large PDFs or PDFs with many annotations will require efficient processing to maintain good performance.
Deliverables
A complete, functioning web application hosted on Replit
Well-commented source code that explains your approach
A README.md explaining how the application works and any limitations
Basic documentation on the PDF.js integration approach you used
Instructions for testing the application with example PDFs
Evaluation Criteria
Functionality: Does it correctly extract images from PDF annotations?
Code Quality: Is the code well-structured, readable, and maintainable?
User Experience: Is the interface intuitive and responsive?
Robustness: Does it handle edge cases and errors gracefully?
Documentation: Is the code and approach well-documented?