Python3 Image Crop Tool

image-crop-tool.py

#!/usr/bin/env python3

# Image Crop Tool v1.0
# (C) Rambling Indie Games, LLC
# Developed by Richard Marks <richard@ramblingindie.games>

# depends on Pillow third party library for PIL in Python 3.6
# pip3 install pillow
from PIL import Image
import json
import os
import sys
import glob
import pathlib
import time

def is_not_transparent(image, x, y):
	pixel = image.getpixel((x, y))
	if pixel[3] != 0:
		return True
	return False

def find_left_crop_coordinate(image, width, height):
	for x in range(width):
		for y in range(height):
			if is_not_transparent(image, x, y):
				return x
			
def find_top_crop_coordinate(image, width, height):
	for y in range(height):
		for x in range(width):
			if is_not_transparent(image, x, y):
				return y
			
def find_right_crop_coordinate(image, width, height):
	for x in range(width - 1, -1, -1):
		for y in range(height):
			if is_not_transparent(image, x, y):
				return x + 1
			
def find_bottom_crop_coordinate(image, width, height):
	for y in range(height - 1, -1, -1):
		for x in range(width):
			if is_not_transparent(image, x, y):
				return y + 1

def process_image(filename, output_path):
	start_time = time.time()
	image = Image.open(filename)
	width, height = image.size

	left_crop = find_left_crop_coordinate(image, width, height)
	right_crop = find_right_crop_coordinate(image, width, height)
	top_crop = find_top_crop_coordinate(image, width, height)
	bottom_crop = find_bottom_crop_coordinate(image, width, height)

	crop_width = right_crop - left_crop
	crop_height = bottom_crop - top_crop

	# print('filename:', filename)
	# print('format:', image.format)
	# print('mode:', image.mode)
	# print('size:', str(width) + 'x' + str(height))
	# print('crop size:', str(crop_width) + 'x' + str(crop_height))
	# print('x offset:', left_crop)
	# print('y offset:', top_crop)
	
	cropped_image = image.crop((
		left_crop,
		top_crop,
		right_crop,
		bottom_crop
	))

	base, ext = os.path.splitext(os.path.basename(filename))

	# print('base:', base)
	# print('ext:', ext)
	# print('basename', os.path.basename(filename))

	crop_filename = base + '_crop.png'

	cropped_image.save(os.path.join(output_path, crop_filename), 'PNG')

	image_data = {
		'id': base,
		'filename': crop_filename,
		'width': crop_width,
		'height': crop_height,
		'x': left_crop,
		'y': top_crop
	}

	end_time = time.time()
	process_time = end_time - start_time
	print("Processed %s (%.2fs)" % (filename, process_time))
	return image_data

def main():
	# scriptname [source-path] [output-path]
	source_path = './*.png'
	output_path = './output'
	if len(sys.argv) > 1:
		source_path = os.path.join(sys.argv[1], '*.png')
	if len(sys.argv) > 2:
		output_path = sys.argv[2]
	print('source path:', source_path)
	print('output path:', output_path)

	pathlib.Path(output_path).mkdir(parents=True, exist_ok=True)

	data = {}
	data['meta'] = {}
	data['meta']['version'] = '1.0.0'

	data['images'] = []

	for filename in glob.glob(source_path):
		data['images'].append(
			process_image(filename, output_path)
		)

	with open(os.path.join(output_path, 'images.json'), 'w') as outfile:
		json.dump(data, outfile, indent=2)
	
if __name__ == "__main__":
	start_time = time.time()
	main()
	print("--- Finished in %.2fs ---" % (time.time() - start_time))