Added palette support

cc-pic.py

@@ -1,11 +1,16 @@
 #!/usr/bin/env python3
 
 from typing import BinaryIO, TextIO
-from PIL import Image
+from PIL import Image, ImageColor
 from argparse import ArgumentParser, RawTextHelpFormatter
 from textwrap import dedent
 from functools import lru_cache
 
+try:
+    PALETTE_ADAPTIVE = Image.Palette.ADAPTIVE
+except Exception:
+    PALETTE_ADAPTIVE = Image.ADAPTIVE
+
 
 class Converter:
     CC_COLORS = [
@@ -46,11 +51,30 @@ class Converter:
         17, 17, 17
     ]
 
+    DEFAULT_GRAYSCALE_PALETTE = [
+        0xf0, 0xf0, 0xf0,
+        0x9d, 0x9d, 0x9d,
+        0xbe, 0xbe, 0xbe,
+        0xbf, 0xbf, 0xbf,
+        0xb8, 0xb8, 0xb8,
+        0x76, 0x76, 0x76,
+        0xd0, 0xd0, 0xd0,
+        0x4c, 0x4c, 0x4c,
+        0x99, 0x99, 0x99,
+        0x87, 0x87, 0x87,
+        0xa9, 0xa9, 0xa9,
+        0x77, 0x77, 0x77,
+        0x65, 0x65, 0x65,
+        0x6e, 0x6e, 0x6e,
+        0x76, 0x76, 0x76,
+        0x11, 0x11, 0x11
+    ]
+
     PIX_BITS = [[1, 2], [4, 8], [16, 0]]
 
     MAX_DIFF = 3 * 255
 
-    def __init__(self, image: Image.Image, palette: list[int] | int = Image.ADAPTIVE):
+    def __init__(self, image: Image.Image, palette: list[int] | int = PALETTE_ADAPTIVE):
         if isinstance(palette, list):
             img_pal = Image.new("P", (1, 1))
             img_pal.putpalette(palette)
@@ -246,6 +270,25 @@ def main():
                 -p fill         Stretch to fill"""
         ),
     )
+    parser.add_argument(
+        "-P",
+        dest="palette",
+        default="auto",
+        help=dedent(
+            """\
+            Palette to be used for that conversion.
+            Should be 16 colors or less
+            Valid options are:
+                -P auto         Determine palette automatically
+                -P default      Use default CC:Tweaked color palette
+                -P defaultgray  Use default CC:Tweaked grayscale palette
+                -P "list:#RRGGBB,#RRGGBB,..."   Use a set list of colors
+                -P "cpi:path"   Load palette from a CCPI file
+                -P "gpl:path"   Parse GIMP palette file and use first 16 colors
+                -P "txt:path"   Load palette from a list of hex values
+            """
+        )
+    )
     parser.add_argument("image_path")
     parser.add_argument("output_path")
 
@@ -320,9 +363,34 @@ def main():
             else:
                 pass
 
-            palette = Image.Palette.ADAPTIVE
+            palette = PALETTE_ADAPTIVE
             if args.cpi_version == -2:
+                args.palette = "default"
+
+            if args.palette == "auto":
+                palette = PALETTE_ADAPTIVE
+            elif args.palette == "default":
                 palette = Converter.DEFAULT_PALETTE
+            elif args.palette == "defaultgray":
+                palette = Converter.DEFAULT_GRAYSCALE_PALETTE
+            elif args.palette.startswith("txt:"):
+                with open(args.palette[4:], "r") as fp:
+                    palette = []
+                    for line in fp:
+                        palette += ImageColor.getcolor(line.strip(), "RGB")  # type: ignore
+                        assert len(palette) <= 16 * 3
+            elif args.palette.startswith("list:"):
+                palette = []
+                for c in args.palette[5:].split(","):
+                    palette += ImageColor.getcolor(c, "RGB")  # type: ignore
+                    assert len(palette) <= 16 * 3
+            elif args.palette.startswith("cpi:"):
+                raise ValueError("not implemented yet")
+            elif args.palette.startswith("gpl:"):
+                raise ValueError("not implemented yet")
+            else:
+                raise ValueError(f"invalid palette identifier: {args.palette!r}")
+
             converter = Converter(canv, palette)
             converter._img.save("/tmp/_ccpictmp.png")
             if args.textmode: