What is a good and free image editor? (Alternative to Photoshop)
Does anyone know of any free image viewer (or preferably editor) that can work with very large images (say, 30,000 x 30,000 pixel PNG or JPGs)? I know Photoshop works with those well and renders them very well, but other programs are either slow or use huge amounts (gigabytes) of memory. The built-in Windows previewer is almost good, but it's still a bit slow and uses a bit too much memory, and it's also not an editor... does anyone know of any such software?
Edit: A programming library would also be fine, so long as it works for large images.