Python - Find The Closest Color To A Color, From Giving List Of Colors

I have a list of 20 colors, each is like this (0,0,0)(rgb) but with different values, and i need to find the closest to the color i am giving, for example (200, 191, 231). problem

Solution 1:

You want to find the sum of the absolute difference between the red, green and blue numbers and choose the smallest one.

from math import sqrt

COLORS = (
    (181, 230, 99),
    (23, 186, 241),
    (99, 23, 153),
    (231, 99, 29),
)

defclosest_color(rgb):
    r, g, b = rgb
    color_diffs = []
    for color in COLORS:
        cr, cg, cb = color
        color_diff = sqrt((r - cr)**2 + (g - cg)**2 + (b - cb)**2)
        color_diffs.append((color_diff, color))
    returnmin(color_diffs)[1]

closest_color((12, 34, 156))
# => (99, 23, 153)

closest_color((23, 145, 234))
# => (23, 186, 241)

EDIT: Improved code and used Euclidian distance calculation Sven mentioned above instead of basic diff sum.

Solution 2:

Fast, efficient and clean solution

Lets say we have:

list_of_colors = [[255,0,0],[150,33,77],[75,99,23],[45,88,250],[250,0,255]]

For fast processing use numpy and transform into numpy array

import numpy as np

desired color

color = [155,155,155]

Complete code

import numpy as np

list_of_colors = [[255,0,0],[150,33,77],[75,99,23],[45,88,250],[250,0,255]]
color = [155,155,155]

def closest(colors,color):
    colors = np.array(colors)
    color = np.array(color)
    distances = np.sqrt(np.sum((colors-color)**2,axis=1))
    index_of_smallest = np.where(distances==np.amin(distances))
    smallest_distance = colors[index_of_smallest]
    return smallest_distance 

closest_color = closest(list_of_colors,color)
print(closest_color )

This algorithm is without loops and is super fast as it uses numpy

Solution 3:

Even faster using jit

from numba import jit

colors = np.array(colors)
color = np.array(color)

@jitdefclosest(colors,color):
    distances = np.sqrt(np.sum((colors-color)**2,axis=1))
    index_of_smallest = np.where(distances==np.amin(distances))
    smallest_distance = colors[index_of_smallest]
    return smallest_distance