I was recently working with user-editable texture masks, and I was a little surprized when I didn’t find a specialized image file format for 1-bit (monochrome) images. So, here’s a file format proposal:

  • File extension: .1bit
  • Magic header: 4 bytes: “1bit” in ASCII
  • 2 bytes for the width of the image
  • 2 bytes for the height of the image
  • 1 byte for number of channels
  • RLE-compressed binary data
  • Optional:
    • 1 byte for the length of the comment
    • 1-254 bytes of text comment because ebin memes

Am I missing anything?

I wonder how hard would it be to create a Photoshop plugin for this. A C or C# implementation would be fairly trivial, though it can be a bit tricky when doing 1-bit RLE compression.