Ksnip is a Qt based cross-platform screenshot tool that provides many annotation features for your screenshots.

Features:

• Supports Linux (X11, Plasma Wayland, GNOME Wayland and xdg-desktop-portal Wayland), Windows and macOS.
• Taking screenshot of a custom rectangular area that can be drawn with mouse cursor.
• Taking screenshot of last selected rectangular area without selecting again.
• Taking screenshot of the screen/monitor where the mouse cursor is currently located.
• Taking screenshot of full screen, including all screens/monitors.
• Taking screenshot of window that currently has focus.
• Taking screenshot of window under mouse cursor.
• Take screenshot with or without mouse cursor.
• Capture mouse cursor as annotation item that can be moved and deleted.
• Customizable capture delay for all capture options.
• Upload screenshots directly to imgur.com in anonymous or user mode.
• Upload screenshots via custom user defined scripts.
• Command line support, for taking screenshot and saving it to default location, filename and format.
• Filename wildcards for Year ($Y), Month ($M), Day ($D), Time ($T) and Counter (multiple # characters for number with zero leading padding).
• Print screenshot or save is to pdf/ps.
• Annotate screenshots with pen, marker, rectangles, ellipses, texts and other tools.
• Annotate screenshots with stickers and add custom stickers.
• Obfuscate image regions with blur and pixelate.
• Add effects to image (Drop Shadow, Grayscale, invert color or Border).
• Add watermarks to captured images.
• Global HotKeys for taking Screenshots (Currently only for Windows and X11).
• Tabs for Screenshots and images.
• Open existing images via dialog, drag-and-drop or paste from clipboard.
• Run as single instance application (secondary instances send cli parameter to primary instance).
• Pin Screenshots in Frameless windows that stay on top of other windows.
• User-defined actions for taking screenshot and post-processing.
• OCR support through plugin (Window and Linux/Unix).
• Many configuration options.