What is a WEBP file?

WEBP is a file image format created by Google (introduced in 2010) providing both lossy and lossless compression, usually producing much smaller file sizes than JPEG or PNG while keeping similar visual quality. 

WEBP is based on the RIFF (the famous Resource Interchange File Format) container structure.

Making a PNG Image Smaller

Converting a PNG to a 16 colour BMP bitmap reduces its size by between 40%-60%. PNG is a format that supports lossless compression.

GIMP for Windows

The Current Stable Version and Other Logistics

Current stable version as of 22 May 2016 is 2.8.16. The GIMP installer for Windows is around 100MB. GIMP has its own wiki. On Windows GIMP installs to C:\Program Files and subdirectory GIMP 2 by default. GIMP supports the writing of plugins in Python. Wilber the dog is the GIMP mascot.

Compelling Reasons to use GIMP

Among the many interesting and useful features of GIMP is the ability to re-save JPEG images at user-controllable levels of quality.

Rotate a Scanned Image in Windows 10

To rotate a scanned image in Windows 10, there is no need to use a paint package. Simply right click on the file in Windows Explorer and do a "Rotate right" or "Rotate left".