Many companies use this software for editing photos.
I use this for our company work and this works perfectly for image editing process.
GIMP - GIMP is a multiplatform photo manipulation tool.
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.
Darktable - darktable is an open source photography workflow application and raw developer.
Krita - Krita is a professional FREE and open source painting program. It is made by artists that want to seaffordable art tools for everyone. Concept art. texture and matte painters, illustrations and comics.
Caesium Image Compressor - Compress your pictures up to 90% without visible quality loss.