tornado 之 图片验证码

生成图片的验证码,进行图像处理,需使用Pillow

  1 #!/usr/bin/env python
  2 #coding:utf-8
  3 
  4 import os
  5 import random
  6 from PIL import Image, ImageDraw, ImageFont, ImageFilter
  7 
  8 _letter_cases = "abcdefghjkmnpqrstuvwxy"  # 小写字母,去除可能干扰的i,l,o,z
  9 _upper_cases = _letter_cases.upper()  # 大写字母
 10 _numbers = ''.join(map(str, range(3, 10)))  # 数字
 11 init_chars = ''.join((_letter_cases, _upper_cases, _numbers))
 12 
 13 def create_validate_code(size=(120, 30),
 14                          chars=init_chars,
 15                          img_type="GIF",
 16                          mode="RGB",
 17                          bg_color=(255, 255, 255),
 18                          fg_color=(0, 0, 255),
 19                          font_size=18,
 20                          font_type=os.path.join(os.path.dirname(__file__),"Monaco.ttf"),
 21                          length=4,
 22                          draw_lines=True,
 23                          n_line=(1, 2),
 24                          draw_points=True,
 25                          point_chance = 2):
 26     # font_type =os.path.join(os.path.dirname(__file__), font_type)
 27     '''
 28     @todo: 生成验证码图片
 29     @param size: 图片的大小,格式(宽,高),默认为(120, 30)
 30     @param chars: 允许的字符集合,格式字符串
 31     @param img_type: 图片保存的格式,默认为GIF,可选的为GIF,JPEG,TIFF,PNG
 32     @param mode: 图片模式,默认为RGB
 33     @param bg_color: 背景颜色,默认为白色
 34     @param fg_color: 前景色,验证码字符颜色,默认为蓝色#0000FF
 35     @param font_size: 验证码字体大小
 36     @param font_type: 验证码字体,默认为 ae_AlArabiya.ttf
 37     @param length: 验证码字符个数
 38     @param draw_lines: 是否划干扰线
 39     @param n_lines: 干扰线的条数范围,格式元组,默认为(1, 2),只有draw_lines为True时有效
 40     @param draw_points: 是否画干扰点
 41     @param point_chance: 干扰点出现的概率,大小范围[0, 100]
 42     @return: [0]: PIL Image实例
 43     @return: [1]: 验证码图片中的字符串
 44     '''
 45 
 46     width, height = size # 宽, 高
 47     img = Image.new(mode, size, bg_color) # 创建图形
 48     draw = ImageDraw.Draw(img) # 创建画笔
 49 
 50     def get_chars():
 51         '''生成给定长度的字符串,返回列表格式'''
 52         return random.sample(chars, length)
 53 
 54     def create_lines():
 55         '''绘制干扰线'''
 56         line_num = random.randint(*n_line) # 干扰线条数
 57 
 58         for i in range(line_num):
 59             # 起始点
 60             begin = (random.randint(0, size[0]), random.randint(0, size[1]))
 61             #结束点
 62             end = (random.randint(0, size[0]), random.randint(0, size[1]))
 63             draw.line([begin, end], fill=(0, 0, 0))
 64 
 65     def create_points():
 66         '''绘制干扰点'''
 67         chance = min(100, max(0, int(point_chance))) # 大小限制在[0, 100]
 68 
 69         for w in range(width):
 70             for h in range(height):
 71                 tmp = random.randint(0, 100)
 72                 if tmp > 100 - chance:
 73                     draw.point((w, h), fill=(0, 0, 0))
 74 
 75     def create_strs():
 76         '''绘制验证码字符'''
 77         c_chars = get_chars()
 78         strs = ' %s ' % ' '.join(c_chars) # 每个字符前后以空格隔开
 79 
 80         font = ImageFont.truetype(font_type, font_size)
 81         font_width, font_height = font.getsize(strs)
 82 
 83         draw.text(((width - font_width) / 3, (height - font_height) / 3),
 84                     strs, font=font, fill=fg_color)
 85 
 86         return ''.join(c_chars)
 87 
 88     if draw_lines:
 89         create_lines()
 90     if draw_points:
 91         create_points()
 92     strs = create_strs()
 93 
 94     # 图形扭曲参数
 95     params = [1 - float(random.randint(1, 2)) / 100,
 96               0,
 97               0,
 98               0,
 99               1 - float(random.randint(1, 10)) / 100,
100               float(random.randint(1, 2)) / 500,
101               0.001,
102               float(random.randint(1, 2)) / 500
103               ]
104     img = img.transform(size, Image.PERSPECTIVE, params) # 创建扭曲
105 
106     img = img.filter(ImageFilter.EDGE_ENHANCE_MORE) # 滤镜,边界加强(阈值更大)
107 
108     return img, strs
help/check_code.py
 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>用户登录</title>
 6 </head>
 7 <body>
 8 <p><input type="text" name="username" placeholder="用户名"></p>
 9 <p><input type="password" name="password" placeholder="密码"></p>
10 <p>
11     <input type="text" name="chkcode" placeholder="验证码">
12     <img src="/check_code" style="cursor: pointer" onclick="this.setAttribute('src','/check_code?nocache='+Math.random());">
13 </p>
14 </body>
15 </html>
views/login.html
 1 class CheckCodeHandler(BaseHandler):
 2     def get(self, *args, **kwargs):
 3         import io
 4         from TornadoTest3.helper import check_code
 5         mstream = io.BytesIO()
 6         # 创建图片,并写入验证码
 7         img, code = check_code.create_validate_code()
 8         # 将图片对象写入到内存
 9         img.save(mstream, "GIF")
10         self.write(mstream.getvalue())

 

posted @ 2017-04-03 10:54  taibai  阅读(305)  评论(0编辑  收藏  举报