How Does PDF Image Extraction Work?
Reading supported image drawing operations with PDF.js
The browser loads the PDF with PDF.js, scans page drawing operations, and reads supported image objects. It then draws decoded pixels to a canvas and exports each image as a PNG file.
- Image detection: The extractor checks image drawing operations exposed by PDF.js. Some masks, patterns, or unusual image structures may not be available.
- Pixel reconstruction: Supported decoded image pixels are rebuilt as PNG. This is not a byte-for-byte copy of the original embedded image stream.
- Download choices: Save individual images or selected images together in a ZIP archive. JPG export is optional and uses lossy compression.