GIMP Tutorial: How To Zoom In On An Area Of An Image.
How to Zoom in on a picture and & reposition or recentre. Re-scale.
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.