pokemon-color-search/ingest.py

#!/usr/bin/env python3
from collections import namedtuple

from PIL import Image

from convert import rgb_to_cieluv


def is_outline(r: int, g: int, b: int, a: int) -> bool:
    # returns true if a pixel is transparent or pure black
    return a == 0 or (r, g, b) == (0, 0, 0)


def x_metric(pixels: list[tuple[float, float, float]]) -> float:
    # X metric - the mean squared Euclidean norm
    # computed as the sum of the squares of the components of the pixels,
    # normalized by the number of pixels
    return sum(comp * comp for pix in pixels for comp in pix) / len(pixels)


def y_metric(pixels: list[tuple[float, float, float]]) -> tuple[float, float, float]:
    # Y metric - the mean pixel of the image
    return tuple(sum(p[i] for p in pixels) / len(pixels) for i in range(3))


ImageInfo = namedtuple(
    "ImageInfo", ["name", "xrgb", "xluv", "yr", "yg", "yb", "yl", "yu", "yv"]
)


def ingest_png(file_name: str) -> ImageInfo:
    print(f"Ingesting {file_name}")

    # image name - strip leading path and trailing extension
    name = file_name.rsplit("/", maxsplit=1)[1].split(".", maxsplit=1)[0]

    # read non-outline pixels of image
    rgb_pixels = [
        (r, g, b)
        for r, g, b, a in Image.open(file_name).convert("RGBA").getdata()
        if not is_outline(r, g, b, a)
    ]

    # convert RGB pixels to CIELUV values
    luv_pixels = [rgb_to_cieluv(*p) for p in rgb_pixels]

    # compute and return metrics
    xrgb = x_metric(rgb_pixels)
    xluv = x_metric(luv_pixels)
    yr, yg, yb = y_metric(rgb_pixels)
    yl, yu, yv = y_metric(luv_pixels)
    return ImageInfo(
        name=name,
        xrgb=xrgb,
        xluv=xluv,
        yr=yr,
        yg=yg,
        yb=yb,
        yl=yl,
        yu=yu,
        yv=yv,
    )


if __name__ == "__main__":
    import csv
    import os
    import sys

    dir = "pngs" if len(sys.argv) < 2 else sys.argv[1]

    data = [
        ingest_png(dir + "/" + fn)
        for f in os.listdir(dir)
        if (fn := os.fsdecode(f)).endswith(".png")
    ]

    with open("database.csv", "w") as outfile:
        writer = csv.writer(outfile, delimiter=",", quotechar="'")
        writer.writerows([d.name, d.xrgb, d.yr, d.yg, d.yb] for d in data)

    with open("database-luv.csv", "w") as outfile:
        writer = csv.writer(outfile, delimiter=",", quotechar="'")
        writer.writerows([d.name, d.xluv, d.yl, d.yu, d.yv] for d in data)

    with open("database.js", "w") as outfile:
        outfile.write("const database = [\n")
        for info in data:
            fields = ", ".join(
                (
                    f'name: "{info.name}"',
                    f"xRGB: {info.xrgb}",
                    f"xLUV: {info.xluv}",
                    f"yRGB: [ {info.yr}, {info.yg}, {info.yb} ]",
                    f"yLUV: [ {info.yl}, {info.yu}, {info.yv} ]",
                )
            )
            outfile.write(f"  {{ {fields} }},\n")
        outfile.write("];\n")