Every now and then I find myself trying to figure out what's contained in a file, and it's something like a tile based map, or a graphical image that I know should be visually identifiable, if only I had a program that could show it to me in the right format.
Specifically, after recently playing through a game called Aspetra, I wanted to take apart its game maps to see if I missed anything. This isn't the first time I've had this urge; not too long ago I made some maps and a guide for another game I'd been playing.
Usually when this kind of need comes up, maybe I try a hex editor and resize the rows until it looks like something lines up, or I try writing scripts to process the file into something I can use, or maybe I just squint at the data for a while until I have an idea.
This time I thought I should just write the tool I always wish I had when this comes up. I usually felt like building something like this was too much effort just to inspect one game, but now that I've written it I can use this any time I feel the need to go digging in game data! Once I had it working I found it was remarkably fast and easy to get a rough look at the map and graphics data from Aspetra.
Binxelview lets you define a pixel of your image as an assembly of bits from the data file with arbitrary layout. Once you've picked out a pixel format it will just show you the whole file using that format. With a little bit of experimentation many types of uncompressed graphics data can be quickly found this way.
It's not really a generic image data tool, it's purpose is inspecting unknown formats. You may notice the colours are weird in my screenshot, but this is intended for finding any gridlike data, not just graphics. You can customize the colour palette if you need to, but my goal was just to quickly spot the visual structure. It's a tool for my first step in a process of analysis.
I'm making it free and open source for anyone else that might need it. It was written with C♯ and the build I've made is for Windows 7. Give it a try! Maybe open up an NES ROM or some files from an old video game and see what you can find?