The Obsidian OCR plugin adds optical character recognition (OCR) capabilities to Obsidian, allowing you to search for text within images and PDFs. By integrating Tesseract, the plugin automatically processes new image and PDF files added to your vault. It features customizable settings such as adjusting OCR processes, image quality, and image density. The plugin supports multiple OCR providers, with Tesseract as the default, and offers flexibility in configuration to cater to different OCR needs.