GIMP: Convert A Color Image To Black And White.
How to create a black and white image from a colour image. A Gimp beginners tutorial.
GIMP (GNU Image Manipulation Program) is a free and open-source raster graphics editor used for image retouching and editing, free-form drawing, converting between different image formats, and more specialized tasks.
GIMP is released under GPLv3+ licenses and is available for Linux, macOS, and Microsoft Windows.
