resize_pics.py

#!/usr/bin/env python
#-*- coding:utf-8 -*-
#Author: Lei Zhang <[email protected]>
 
import sys
import os
import signal
import argparse
from math import floor
from shutil import copyfile, rmtree
from traceback import print_exc
import multiprocessing
from multiprocessing import Pool
from cStringIO import StringIO
 
from PIL import Image
 
def log_status(func):
    def _(src, dest, cfg):
        ret = None
        process = multiprocessing.current_process()
        msg = StringIO()
        msg.write('[%s-%s]convert %s...' % (process.name, process.pid, src))
        try:
            if not cfg.dry:
                ret = func(src, dest, cfg)
        except Exception, e:
            msg.write('Error')
            print_exc(e, msg)
            print msg.getvalue()
        else:
            msg.write('Ok')
            print msg.getvalue()
            return ret
    return _
 
 
def file_filter(filename):
 
    file, ext = os.path.splitext(filename)
 
    if ext.lower() in ('.jpg') and os.path.isfile(filename):
        return True
    return False
 
BASE=2000.0
 
def run(src, dest, cfg):
    convert(src, dest, cfg)
 
@log_status
def convert(src, dest, cfg):
    im = Image.open(src)
    width, heigh = im.size
    if min(width, heigh) < BASE:
        copyfile(src, dest)
        return
 
    rate = min(width, heigh) / BASE
    new_size = ( int(floor(width/rate)), int(floor(heigh/rate)))
    resize_img = im.resize(new_size, Image.ANTIALIAS)
    resize_img.save(dest, quality=98)
 
def mkdirs(path, clean=False):
    if os.path.exists(path):
        if not clean:
            return
        else:
            rmtree(path)
    os.makedirs(path)

def main(cfg):
    pool = Pool(cfg.thread_num)
    # handle Ctrl+C sinal
    def handler(signum, frame):
        pool.terminator()
    signal.signal(signal.SIGINT, handler)

    def callback(context, dirname, names):
        pool = context['pool']
        dest = os.path.abspath(context['cfg'].dest)
        abssrc = os.path.abspath(cfg.src)
        dirname = os.path.abspath(dirname)
        dest = os.path.join(dest, dirname[len(abssrc)+1:])
        if not cfg.dry:
            mkdirs(dest)
        for name in names:
            src_full = os.path.join(dirname, name)
            dest_full = os.path.join(dest, name)
            if not file_filter(src_full):
                break
            pool.apply_async(run, (src_full, dest_full, cfg))

    context = dict(pool=pool, cfg=cfg)
    os.path.walk(cfg.src, callback, context)
 
    pool.close()
    pool.join()
 
if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='')
    parser.add_argument('-n', '--dry-run', default=False, action="store_true",\
            dest='dry')
    parser.add_argument('-t', '--thread-nums', default=4, metavar='N', dest='thread_num')
    parser.add_argument('src')
    parser.add_argument('dest')
    cfg = parser.parse_args(sys.argv[1:])
    main(cfg)