recolor/main.py

from skimage.io import imread
from scipy.stats import moment
import numpy as np

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


def centeroidnp(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 start
    index = np.random.choice(data.shape[0], count, replace=False)
    means = data[index]
    data = np.delete(data, index, axis=0)

    distance_delta = 100
    means_distance = 0
    while distance_delta > 0.1:
        print(f"new iteration, distance moved: {distance_delta}")
        # Initialize cluster map
        clusters = {}
        for m in means:
            clusters[str(m)] = []

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

        # Find the centeroid of each mean
        new_means = []
        previous_distance = means_distance
        means_distance = 0
        for mean in means:
            mean_key = str(mean)
            # Clean up the results a little bit
            clusters[mean_key] = np.stack(clusters[str(mean)])
            # Calculate new mean
            raw_mean = centeroidnp(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)
    print(means)





im = imread("image.png")
starting_resolution = im.shape
raw_pixels = im.reshape(-1, 3)

colors = [[45, 85, 255], [0, 181, 204], [243, 225, 107]]

k_means(raw_pixels, len(colors))