On September 7, 2026, OSChina reported about an open-source PDF reader tool called veil. This tool offers a smart dark mode feature aimed at improving the reading experience in low-light environments, especially for documents containing a large number of images and scanned documents. Its technology is based on PDF.js page-by-page rendering, using CSS color inversion to create dark backgrounds, and utilizing a second canvas to restore the original image pixels in the inverted areas, thereby preserving the original colors of images, charts, and diagrams while inverting the text colors. The OCR capability of this project is provided by Tess...
veil is an open-source PDF reader that offers intelligent dark mode functionality. This project uses PDF.js for page-by-page rendering, generates dark backgrounds using CSS color inversion, and employs a second canvas to restore the original image pixels in the inverted areas, thereby preserving the original colors of images, charts, and diagrams while inverting text colors. This tool is designed for users who need to read PDFs in low-light environments, especially suitable for research documents containing many images and scans. Its OCR capability is provided by Tess...