update readme

readme.txt

@@ -9,32 +9,23 @@ 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...
-there is also paletteId that tell which palette the image used.
 
-usage: sillyimage <input image> [options]
+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:
-  -o, --out
+  -i, --input    input files [required] [may be repeated]
-    output directory
+  -o, --out      output directory [required]
-
+  -h, --help     shows help message and exits 
-  -f, --format 
+  -v, --version  prints version information and exits 
-    specify format {rgb256, rgb16, indexed4, indexed16, indexed256, indexed32a3, indexed8a5}
+  -f, --format   texture format { rgb256, rgb16, indexed4, indexed16, indexed256, indexed32a3, indexed8a5 } [default: "rgb16"]
-
-  -c, --compress
-    specify compression {none, lzsswram, lzssvram, gzip}
-
-  -pid, --palette-id
-    specify the palette id
-
-  -n, --num
-    limit num color regardless of the format
-
-  -v, --verbose
-    enable verbose printing
 
 binary format:
   [string] sillyimg (0x676D69796C6C6973 in hex or 7452728928599042419 in decimal (uint64))
-  [uint8] version (current version is 0)
+  [uint8] version (current version is 13)
   [uint8] format
     0 - RGB256
     1 - RGB16
@@ -44,16 +35,14 @@ binary format:
     5 - INDEXED32A3
     6 - INDEXED8A5
     7 - PALETTE16
-  [uint8] paletteId
   [uint16] width
   [uint16] height
-  [uint8] compression
+  [uint16] palette count
-    0 - none
+  [uint32] palette hash
-    1 - lzss wram
+  [uint32] compress size
-    2 - lzss vram
+  [uint32] original size
-    3 - gzip
+  [palette buffer]
-  [uint32] buffer length
+  [image buffer]
-  [buffer]
 
 TODO:
   [x] bitpacking for indexed format
@@ -61,13 +50,14 @@ TODO:
   [ ] convert image using predefined palette
   [ ] output preview image
   [ ] improve error handling
-  [ ] compression
+  [x] compression
 
-dependecies:
+dependencies:
-  argh (https://github.com/adishavit/argh)
+  argparse (https://github.com/p-ranav/argparse)
-  stb_image, stb_image_writer (https://github.com/nothings/stb)
+  stb_image (https://github.com/nothings/stb)
   libimagequant (https://github.com/ImageOptim/libimagequant)
-  TImer.h from cherno (https://gist.github.com/TheCherno/b2c71c9291a4a1a29c889e76173c8d14)
+  murmurhash.c (https://github.com/jwerle/murmurhash.c)
+  Timer.h from cherno (https://gist.github.com/TheCherno/b2c71c9291a4a1a29c889e76173c8d14)
 
 license:
   GPL v3