7/6/2017 - 9:28 PM

## Pixelate image in python

Pixelate image in python

``````#!/usr/bin/env python

# This script will pixelate most jpg and png images
# It will both show you the result and save it

import sys

import matplotlib.pyplot as plt
import numpy as np
import PIL.Image as Image
import scipy.misc as misc

# boilerplate code to open an image and make it editable
img = Image.open(filename)
data = np.array(img)
return data

def all_square_pixels(row, col, square_h, square_w):
# Every pixel for a single "square" (superpixel)
# Note that different squares might have different dimensions in order to
# not have extra pixels at the edge not in a square. Hence: int(round())
for y in xrange(int(round(row*square_h)), int(round((row+1)*square_h))):
for x in xrange(int(round(col*square_w)), int(round((col+1)*square_w))):
yield y, x

def make_one_square(img, row, col, square_h, square_w):
# Sets all the pixels in img for the square given by (row, col) to that
# square's average color
pixels = []

# get all pixels
for y, x in all_square_pixels(row, col, square_h, square_w):
pixels.append(img[y][x])

# get the average color
av_r = 0
av_g = 0
av_b = 0
for r, g, b in pixels:
av_r += r
av_g += g
av_b += b
av_r /= len(pixels)
av_g /= len(pixels)
av_b /= len(pixels)

# set all pixels to that average color
for y, x in all_square_pixels(row, col, square_h, square_w):
img[y][x] = (av_r, av_g, av_b)

if __name__ == "__main__":
try:
filename = sys.argv[1]
except IndexError:
filename = raw_input("Image to pixelate? ")

# Figure out the dimensions of each square
# We want:
# 1. Square width and height should be about the same
# 2. No leftover pixels at the edges
# This means that some squares might have one more or one less pixel
# depending on rounding
num_cols = int(raw_input("How many squares from left to right? "))
square_w = float(img.shape[1]) / num_cols
num_rows = int(round(img.shape[0] / square_w))
square_h = float(img.shape[0]) / num_rows

# overwrite each square with the average color, one by one
for row in range(num_rows):
for col in range(num_cols):
make_one_square(img, row, col, square_h, square_w)

# show the image
plt.axis('off')
plt.imshow(img)
plt.show()

# save the image
filename_parts = filename.rsplit('.', 1)
filename_parts[0] += '_pixelated'
filename = '.'.join(filename_parts)
print "Saving as", filename
misc.imsave(filename, img)``````