from PIL import Image
import os

def get_size(file):
    #获取文件大小
    size = os.path.getsize(file)
    return size/1024

#拼接输出文件地址
def get_outfile(infile, outfile):
    if outfile:
        return outfile
    dir,sufix = os.path.splitext(infile)
    outfile = '{}-out{}'.format(dir,sufix)
    return outfile

def compress_image(infile, outfile='',mb=150,step=10,quality=80):
    '''不改变图片尺寸压缩到指定大小
    :param infile: 压缩源文件
    :param outfile: 压缩文件保存路径
    :param mb: 压缩目标，KB
    :param step: 每次调整的压缩比率
    :param quality: 初始压缩比率
    :return: 压缩文件地址，压缩文件大小
    '''
    o_size = get_size(infile)
    if o_size <= mb:
        return infile
    outfile = get_outfile(infile,outfile)
    while o_size > mb:
        im = Image.open(infile)
        im.save(outfile, quality = quality)
        if quality - step < 0:
            break
        quality -= step
        o_size = get_size(outfile)

    return outfile, get_size(outfile)

#修改图片尺寸，如果同时有修改尺寸和大小的需求，可以先修改尺寸，再压缩大小
def resize_image(infile, outfile='', x_s = 1376):
    '''
    修改图片尺寸
    :param infile: 图片源文件
    :param outfile: 重设尺寸文件保存地址
    :param x_s: 设置的宽度
    :return:
    '''
    im = Image.open(infile)
    x,y = im.size
    y_s = int(y*x_s/x)
    out = im.resize((x_s,y_s),Image.ANTIALIAS)
    outfile = get_outfile(infile, outfile)
    out.save(outfile)

if __name__ == '__main__':
    compress_image(r'I:\learn\space.jpg')
    #resize_image(r'I:\learn\space.jpg')




