GIMP (GNU Image Manipulation Program) is a free and open-source raster graphics editor used for image retouching and editing, free-form drawing, resizing, cropping, photo-montages, converting between different image formats, and more specialized tasks.
You can get GIMP at GIMP.ORG and Ninite.
There are many resources to learn how to use GIMP including:
- Lynda – Get a free Lynda account though the Louisville Free Public Library,
- Official GIMP tutorials,
- YouTube,
- Meet the GIMP on YouTube,
- Tutor4u on YouTube
- Polygonal Selection
- Path to Selection