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.
Aseprite - Aseprite is an art program dedicated to the creation of pixel art.
Affinity Photo - Affinity is the imaging and design suite for creative professionals exclusively for Mac.
Pixel Art to CSS - Draw and animate pixel art, export the results to CSS
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.
Pixel Art Studio - A purpose-built drawing tool for pixel artists