Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
Google Lens - Discover information about something by taking a photo
Capture2text - Capture2Text enables users to quickly OCR a portion of the screen using a keyboard shortcut.
GImageReader - gImageReader is a simple Gtk/Qt front-end to the Tesseract OCR Engine.
ksnip - Ksnip is a Qt based cross-platform screenshot tool that provides many annotation features for your screenshots. - DamirPorobic/ksnip
OpenScan - FOSS Document Scanner