Resize and combine images to an n by n grid with ImageMagick commands: morgify and convert

combine_images.py

import os
import shutil


# Settings
n, m = 6, 6
input_folder = "input"
tmp_folder = "tmp"
output_image = "combined_image.png"
size = 300

# Remove existing folder
if os.path.exists(tmp_folder):
	shutil.rmtree(tmp_folder)
os.mkdir(tmp_folder)

# Resize images
os.system("mogrify -resize %ix%i -quality 100 -path %s %s" % \
		  (size, size, tmp_folder, os.path.join(input_folder, "*.png")))

# Combine images
command = "convert "
input_files = [path for path in os.listdir(tmp_folder)]

for i in range(n):
	command += "( "
	for j in range(m):
		command += os.path.join(tmp_folder, input_files[i*m + j]) + " "
	command += "+append ) "
command += ("-append %s" % output_image)

print(command)
os.system(command)