recolor/main.py

import argparse
import sys

import numpy as np
from numpy import all, array, uint8
from rich.console import Console
from scipy.stats import moment
from skimage.io import imread, imsave

console = Console()


def save_image(data, name, resolution):
    final_image = data.reshape(resolution)
    imsave(f"{name}.png", final_image)


def find_nearest_point(data, target):
    idx = np.array([calc_distance(p, target) for p in data]).argmin()
    return data[idx]


def centroidnp(arr):
    length = arr.shape[0]
    sum_x = np.sum(arr[:, 0])
    sum_y = np.sum(arr[:, 1])
    sum_z = np.sum(arr[:, 2])
    return sum_x / length, sum_y / length, sum_z / length


def calc_distance(x, y):
    return np.absolute(np.linalg.norm(x - y))


def k_means(data, count):
    # Pick n random points to startA
    idx_data = np.unique(data, axis=0)
    index = np.random.choice(idx_data.shape[0], count, replace=False)
    means = idx_data[index]
    data = np.delete(data, index, axis=0)

    distance_delta = 100
    means_distance = 0
    clusters = {}
    with console.status("[bold blue] Finding means...") as status:
        while distance_delta > 5:
            # Initialize cluster map
            clusters = {}
            for m in means:
                clusters[repr(m)] = []

            # Find closest mean to each point
            for point in data:
                closest = find_nearest_point(means, point)
                clusters[repr(closest)].append(point)

            # Find the centroid of each mean
            new_means = []
            previous_distance = means_distance
            means_distance = 0
            for mean in means:
                mean_key = repr(mean)
                # Clean up the results a little bit
                clusters[mean_key] = np.stack(clusters[mean_key])
                # Calculate new mean
                raw_mean = centroidnp(clusters[mean_key])
                nearest_mean_point = find_nearest_point(data, raw_mean)
                means_distance = means_distance + calc_distance(
                    mean, nearest_mean_point
                )
                new_means.append(nearest_mean_point)
            means_distance = means_distance / float(count)
            distance_delta = abs(previous_distance - means_distance)
            means = np.stack(new_means)

        return means


im = imread("zarin.jpg")
starting_resolution = im.shape
console.log("[blue] Starting with image of size: ", starting_resolution)
raw_pixels = im.reshape(-1, 3)
raw_shape = raw_pixels.shape

colors = np.array(
    [
        np.array([0, 43, 54]),
        np.array([7, 54, 66]),
        np.array([88, 110, 117]),
        np.array([101, 123, 131]),
        np.array([131, 148, 150]),
        np.array([147, 161, 161]),
        np.array([238, 232, 213]),
        np.array([253, 246, 227]),
        np.array([181, 137, 0]),
        np.array([203, 75, 22]),
        np.array([220, 50, 47]),
        np.array([211, 54, 130]),
        np.array([108, 113, 196]),
        np.array([38, 139, 210]),
        np.array([42, 161, 152]),
        np.array([133, 153, 0]),
    ]
)


def main():
    # Find the colors that most represent the image
    color_means = k_means(raw_pixels, len(colors))
    console.log("[green] Found cluster centers: ", color_means)

    # Remap image to the center points
    console.log("[purple] Re-mapping image")
    output_raw = np.zeros_like(raw_pixels)
    for i in range(len(raw_pixels)):
        output_raw[i] = find_nearest_point(color_means, raw_pixels[i])

    # Map means to the colors provided by the user
    pairs = []
    tmp_means = color_means
    for color in colors:
        m = find_nearest_point(tmp_means, color)
        pairs.append((m, color))
        (idxs,) = np.where(np.all(tmp_means == m, axis=1))
        tmp_means = np.delete(tmp_means, idxs, axis=0)

    # Recolor the image
    for pair in pairs:
        (idxs,) = np.where(np.all(output_raw == pair[0], axis=1))
        output_raw[idxs] = pair[1]
    save_image(output_raw, "final", starting_resolution)


if __name__ == "__main__":
    parser = argparse.ArgumentParser(
        prog="Recolor",
        description="Recolor changes the color palette of an image to the one provided by the user",
    )
    color_loader_group = parser.add_mutually_exclusive_group(required=True)
    color_loader_group.add_argument(
        "-f",
        "--file",
        description="A file of RGB color values, with one color per line",
        dest="fpath",
        default=None,
    )
    color_loader_group.add_argument(
        "-l",
        "--list",
        description="A list of RGB color values. Example: '123,90,89 212,7,0'",
        dest="clist",
        default=None,
    )
    main()
    pass

sys.exit(0)