Python实现图片尺寸缩放脚本

# coding=utf-8 import Image import shutil import os   class Graphics:  infile = 'D://myimg.jpg'  outfile = 'D://adjust_img.jpg'   @classmethod  def fixed_size(cls, width, height):   """按照固定尺寸处理图片"""   im = Image.open(cls.infile)   out = im.resize((width, height),Image.ANTIALIAS)   out.save(cls.outfile)   @classmethod  def resize_by_width(cls, w_divide_h):   """按照宽度进行所需比例缩放"""   im = Image.open(cls.infile)   (x, y) = im.size   x_s = x   y_s = x/w_divide_h   out = im.resize((x_s, y_s), Image.ANTIALIAS)   out.save(cls.outfile)   @classmethod  def resize_by_height(cls, w_divide_h):   """按照高度进行所需比例缩放"""   im = Image.open(cls.infile)   (x, y) = im.size   x_s = y*w_divide_h   y_s = y   out = im.resize((x_s, y_s), Image.ANTIALIAS)   out.save(cls.outfile)   @classmethod  def resize_by_size(cls, size):   """按照生成图片文件大小进行处理(单位KB)"""   size *= 1024   im = Image.open(cls.infile)   size_tmp = os.path.getsize(cls.infile)   q = 100   while size_tmp > size and q > 0:    print q    out = im.resize(im.size, Image.ANTIALIAS)    out.save(cls.outfile, quality=q)    size_tmp = os.path.getsize(cls.outfile)    q -= 5   if q == 100:    shutil.copy(cls.infile, cls.outfile)   @classmethod  def cut_by_ratio(cls, width, height):   """按照图片长宽比进行分割"""   im = Image.open(cls.infile)   width = float(width)   height = float(height)   (x, y) = im.size   if width > height:    region = (0, int((y-(y * (height / width)))/2), x, int((y+(y * (height / width)))/2))   elif width < height:    region = (int((x-(x * (width / height)))/2), 0, int((x+(x * (width / height)))/2), y)   else:    region = (0, 0, x, y)    #裁切图片   crop_img = im.crop(region)   #保存裁切后的图片   crop_img.save(cls.outfile)