I’ve been working on some code that generates terrain images, and now I’m generating continents at really high resolutions—100,000x100,000. IrfanView is struggling to handle these images, especially when zooming or converting them. Is there a better solution for quickly handling massive PPM or PNG files?
You could try XnView, or if you’re comfortable with it, look into using libvips for handling those huge images.
There’s now a semi-official cross-platform image viewer for libvips, and it’s pretty easy to use.
What are you planning to do with 10,000 megapixel images? You might want to look into using an image tiling system.
vipsdisp should handle your images pretty well. It has binaries for Windows, or you can get it as a flatpak for *nix. Binary ppm files should open quickly, but PNG might take a bit longer since it’s a slower format.
vipsdisp also has a nice false-color mode, which could work great for terrain images. If you’re working with height data, just open the image, right-click, and go to View / Display control bar. The sliders at the bottom control scale and offset, and the menu has a false-color option and even a log scale, which might be useful.
Make sure to check out the keyboard shortcuts for extra control.