i make this tool for my ds to make loading texture easier...
desgined for my personal use only....
its not really optimized and use really minimal error checking

please use something more stable like ptexconv or grit instead!

since ptexconv and grit just simply convert image data into loose Binary
i tried to create header with the metadata information of the image

the idea is to simply load image data without worrying about image metadata.
the metadata contain basic stuff like width, height, format, etc...

color palette are embedded in the file.
a palette hash is provided. this can be used to comparing
whether another image uses the same palette

usage: sillyimage -i <input image> -o <output dir> [options]

options:
  -i, --input    input files [required] [may be repeated]
  -o, --out      output directory [required]
  -h, --help     shows help message and exits 
  -v, --version  prints version information and exits 
  -f, --format   texture format { rgb256, rgb16, indexed4, indexed16, indexed256, indexed32a3, indexed8a5 } [default: "rgb16"]

binary format:
  [string] sillyimg (0x676D69796C6C6973 in hex or 7452728928599042419 in decimal (uint64))
  [uint8] version (current version is 13)
  [uint8] format
    0 - RGB256
    1 - RGB16
    2 - INDEXED4
    3 - INDEXED16
    4 - INDEXED256
    5 - INDEXED32A3
    6 - INDEXED8A5
    7 - PALETTE16
  [uint16] width
  [uint16] height
  [uint16] palette count
  [uint32] palette hash
  [uint32] compress size
  [uint32] original size
  [palette buffer]
  [image buffer]

TODO:
  [x] bitpacking for indexed format
  [x] bitpacking for alpha indexed format
  [ ] convert image using predefined palette
  [ ] output preview image
  [ ] improve error handling
  [x] compression

dependencies:
  argparse (https://github.com/p-ranav/argparse)
  stb_image (https://github.com/nothings/stb)
  murmurhash.c (https://github.com/jwerle/murmurhash.c)
  Timer.h from cherno (https://gist.github.com/TheCherno/b2c71c9291a4a1a29c889e76173c8d14)

license:
  GPL v3