resize android images

android.py

#from PIL import Image
from wand.image import Image
import sys
import os, os.path

quality = 70

resolutions = {'ldpi':3,'mdpi':4,'hdpi':6,'xhdpi':8, 'xxhdpi':12, 'xxxhdpi':16}

in_scale = 1

def resize(img, ratio):
	global in_scale

	old_width = img.width
	old_height = img.height

	size = int(old_width*ratio/in_scale), int(old_height*ratio/in_scale)
	img.resize(size[0], size[1])

	print 'resize :',old_width,old_height,ratio,' => ',size
	return img

def pngsave(im, file):
	global quality
    
	im.save(filename=file)

def process(in_file):	
	for key in resolutions:
		print key, 'corresponds to', resolutions[key]
		path = out_folder+'/drawable-'+key
		if not os.path.exists(path):
			os.makedirs(path)

		index = in_file.rfind('/')
		if index > -1:
			output_file = in_file[index:]
		else:
			output_file = in_file
		output_file = output_file.replace('-','_')
		print 'processing',in_file,output_file

		try:
			with Image(filename=in_file) as img:
				if key == in_resolution:
					print 'skipping'
				else:
					img = resize(img, resolutions[key]/float(resolutions[in_resolution]))
				pngsave(img, path+'/'+output_file)
		except Exception, e:
			print "Exception !!! : ",e
		

if __name__ == '__main__':
	in_file = sys.argv[1]
	in_resolution = sys.argv[2]
	out_folder = sys.argv[3]

	if len(sys.argv)>4:
		in_scale = float(sys.argv[4])

	if in_file.endswith('/'):
		for root, dirs, files in os.walk(in_file[:in_file.rfind('/')]):
			for file in files:
				in_file = os.path.join(root, file)
				process(in_file)
	else:
		process(in_file)