pixel-art

1"""Pixel art converter — Floyd-Steinberg dithering with preset or named palette.2 3Named hardware palettes (NES, GameBoy, PICO-8, C64, etc.) ported from4pixel-art-studio (MIT) — see ATTRIBUTION.md.5 6Usage (import):7    from pixel_art import pixel_art8    pixel_art("in.png", "out.png", preset="arcade")9    pixel_art("in.png", "out.png", preset="nes")10    pixel_art("in.png", "out.png", palette="PICO_8", block=6)11 12Usage (CLI):13    python pixel_art.py in.png out.png --preset nes14"""15 16from PIL import Image, ImageEnhance, ImageOps17 18try:19    from .palettes import PALETTES, build_palette_image20except ImportError:21    from palettes import PALETTES, build_palette_image22 23 24PRESETS = {25    # ── Original presets (adaptive palette) ─────────────────────────────26    "arcade": {27        "contrast": 1.8, "color": 1.5, "sharpness": 1.2,28        "posterize_bits": 5, "block": 8, "palette": 16,29    },30    "snes": {31        "contrast": 1.6, "color": 1.4, "sharpness": 1.2,32        "posterize_bits": 6, "block": 4, "palette": 32,33    },34    # ── Hardware-accurate presets (named palette) ───────────────────────35    "nes": {36        "contrast": 1.5, "color": 1.4, "sharpness": 1.2,37        "posterize_bits": 6, "block": 8, "palette": "NES",38    },39    "gameboy": {40        "contrast": 1.5, "color": 1.0, "sharpness": 1.2,41        "posterize_bits": 6, "block": 8, "palette": "GAMEBOY_ORIGINAL",42    },43    "gameboy_pocket": {44        "contrast": 1.5, "color": 1.0, "sharpness": 1.2,45        "posterize_bits": 6, "block": 8, "palette": "GAMEBOY_POCKET",46    },47    "pico8": {48        "contrast": 1.6, "color": 1.3, "sharpness": 1.2,49        "posterize_bits": 6, "block": 6, "palette": "PICO_8",50    },51    "c64": {52        "contrast": 1.6, "color": 1.3, "sharpness": 1.2,53        "posterize_bits": 6, "block": 8, "palette": "C64",54    },55    "apple2": {56        "contrast": 1.8, "color": 1.4, "sharpness": 1.2,57        "posterize_bits": 5, "block": 10, "palette": "APPLE_II_HI",58    },59    "teletext": {60        "contrast": 1.8, "color": 1.5, "sharpness": 1.2,61        "posterize_bits": 5, "block": 10, "palette": "TELETEXT",62    },63    "mspaint": {64        "contrast": 1.6, "color": 1.4, "sharpness": 1.2,65        "posterize_bits": 6, "block": 8, "palette": "MICROSOFT_WINDOWS_PAINT",66    },67    "mono_green": {68        "contrast": 1.8, "color": 0.0, "sharpness": 1.2,69        "posterize_bits": 5, "block": 6, "palette": "MONO_GREEN",70    },71    "mono_amber": {72        "contrast": 1.8, "color": 0.0, "sharpness": 1.2,73        "posterize_bits": 5, "block": 6, "palette": "MONO_AMBER",74    },75    # ── Artistic palette presets ────────────────────────────────────────76    "neon": {77        "contrast": 1.8, "color": 1.6, "sharpness": 1.2,78        "posterize_bits": 5, "block": 6, "palette": "NEON_CYBER",79    },80    "pastel": {81        "contrast": 1.2, "color": 1.3, "sharpness": 1.1,82        "posterize_bits": 6, "block": 6, "palette": "PASTEL_DREAM",83    },84}85 86 87def pixel_art(input_path, output_path, preset="arcade", **overrides):88    """Convert an image to retro pixel art.89 90    Args:91        input_path: path to source image92        output_path: path to save the resulting PNG93        preset: one of PRESETS (arcade, snes, nes, gameboy, pico8, c64, ...)94        **overrides: optionally override any preset field. In particular:95            palette: int (adaptive N colors) OR str (named palette from PALETTES)96            block:   int pixel block size97            contrast / color / sharpness / posterize_bits: numeric enhancers98 99    Returns:100        The resulting PIL.Image.101    """102    if preset not in PRESETS:103        raise ValueError(104            f"Unknown preset {preset!r}. Choose from: {sorted(PRESETS)}"105        )106    cfg = {**PRESETS[preset], **overrides}107 108    img = Image.open(input_path).convert("RGB")109 110    img = ImageEnhance.Contrast(img).enhance(cfg["contrast"])111    img = ImageEnhance.Color(img).enhance(cfg["color"])112    img = ImageEnhance.Sharpness(img).enhance(cfg["sharpness"])113    img = ImageOps.posterize(img, cfg["posterize_bits"])114 115    w, h = img.size116    block = cfg["block"]117    small = img.resize(118        (max(1, w // block), max(1, h // block)),119        Image.NEAREST,120    )121 122    # Quantize AFTER downscale so Floyd-Steinberg aligns with final pixel grid.123    pal = cfg["palette"]124    if isinstance(pal, str):125        # Named hardware/artistic palette126        pal_img = build_palette_image(pal)127        quantized = small.quantize(palette=pal_img, dither=Image.FLOYDSTEINBERG)128    else:129        # Adaptive N-color palette (original behavior)130        quantized = small.quantize(colors=int(pal), dither=Image.FLOYDSTEINBERG)131 132    result = quantized.resize((w, h), Image.NEAREST)133    result.save(output_path, "PNG")134    return result135 136 137def main():138    import argparse139    p = argparse.ArgumentParser(description="Convert image to pixel art.")140    p.add_argument("input")141    p.add_argument("output")142    p.add_argument("--preset", default="arcade", choices=sorted(PRESETS))143    p.add_argument("--palette", default=None,144                   help=f"Override palette: int or name from {sorted(PALETTES)}")145    p.add_argument("--block", type=int, default=None)146    args = p.parse_args()147 148    overrides = {}149    if args.palette is not None:150        try:151            overrides["palette"] = int(args.palette)152        except ValueError:153            overrides["palette"] = args.palette154    if args.block is not None:155        overrides["block"] = args.block156 157    pixel_art(args.input, args.output, preset=args.preset, **overrides)158    print(f"Wrote {args.output}")159 160 161if __name__ == "__main__":162    main()163