If you are one of those people who likes to edit the images and fond of open source software, you have a number of alternatives available. With GIMP being the most well known in the community, there are other options also available like:
- Blender (3D content)
- PaintSupreme (commercial but cheap and worth checking out)
Online photo editors or digital art:
- Pixlr (has Chrome webapp)
To view high-res images in the browser without scrolling or zoom only specific portion of an image, try Zoom.it.