validate_code.py

#!/usr/bin/env python

#coding=utf-8

import random

import Image, ImageDraw, ImageFont, ImageFilter



_letter_cases = "abcdefghjkmnpqrstuvwxy" # 小写字母，去除可能干扰的i，l，o，z

_upper_cases = _letter_cases.upper() # 大写字母

_numbers = ''.join(map(str, range(3, 10))) # 数字

init_chars = ''.join((_letter_cases, _upper_cases, _numbers))

fontType="/usr/share/fonts/truetype/freefont/FreeSans.ttf"



def create_validate_code(size=(120, 30),

                             chars=init_chars,

                             img_type="GIF",

                             mode="RGB",

                             bg_color=(255, 255, 255),

                             fg_color=(0, 0, 255),

                             font_size=18,

                             font_type=fontType,

                             length=4,

                             draw_lines=True,

                             n_line=(1, 2),

                             draw_points=True,

                             point_chance = 2):

  '''

  @todo: 生成验证码图片

  @param size: 图片的大小，格式（宽，高），默认为(120, 30)

  @param chars: 允许的字符集合，格式字符串

  @param img_type: 图片保存的格式，默认为GIF，可选的为GIF，JPEG，TIFF，PNG

  @param mode: 图片模式，默认为RGB

  @param bg_color: 背景颜色，默认为白色

  @param fg_color: 前景色，验证码字符颜色，默认为蓝色#0000FF

  @param font_size: 验证码字体大小

  @param font_type: 验证码字体，默认为 ae_AlArabiya.ttf

  @param length: 验证码字符个数

  @param draw_lines: 是否划干扰线

  @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

  @param draw_points: 是否画干扰点

  @param point_chance: 干扰点出现的概率，大小范围[0, 100]

  @return: [0]: PIL Image实例

  @return: [1]: 验证码图片中的字符串

  '''



  width, height = size # 宽， 高

  img = Image.new(mode, size, bg_color) # 创建图形

  draw = ImageDraw.Draw(img) # 创建画笔

  if draw_lines:

    create_lines(draw,n_line,width,height)

  if draw_points:

    create_points(draw,point_chance,width,height)

  strs = create_strs(draw,chars,length,font_type, font_size,width,height,fg_color)



  # 图形扭曲参数

  params = [1 - float(random.randint(1, 2)) / 100,

            0,

            0,

            0,

            1 - float(random.randint(1, 10)) / 100,

            float(random.randint(1, 2)) / 500,

            0.001,

            float(random.randint(1, 2)) / 500

            ]

  img = img.transform(size, Image.PERSPECTIVE, params) # 创建扭曲



  img = img.filter(ImageFilter.EDGE_ENHANCE_MORE) # 滤镜，边界加强（阈值更大）



  return img, strs





def create_lines(draw,n_line,width,height):

  '''绘制干扰线'''

  line_num = random.randint(n_line[0],n_line[1]) # 干扰线条数

  for i in range(line_num):

    # 起始点

    begin = (random.randint(0, width), random.randint(0, height))

    #结束点

    end = (random.randint(0, width), random.randint(0, height))

    draw.line([begin, end], fill=(0, 0, 0))



def create_points(draw,point_chance,width,height):

  '''绘制干扰点'''

  chance = min(100, max(0, int(point_chance))) # 大小限制在[0, 100]

 

  for w in xrange(width):

    for h in xrange(height):

      tmp = random.randint(0, 100)

      if tmp > 100 - chance:

        draw.point((w, h), fill=(0, 0, 0))



def create_strs(draw,chars,length,font_type, font_size,width,height,fg_color):

  '''绘制验证码字符'''

  '''生成给定长度的字符串，返回列表格式'''

  c_chars = random.sample(chars, length)

  strs = ' %s ' % ' '.join(c_chars) # 每个字符前后以空格隔开

 

  font = ImageFont.truetype(font_type, font_size)

  font_width, font_height = font.getsize(strs)



  draw.text(((width - font_width) / 3, (height - font_height) / 3),strs, font=font, fill=fg_color)

 

  return ''.join(c_chars)





if __name__ == "__main__":

    code_img = create_validate_code()

    code_img[0].save("validate.gif", "GIF")

    print code_img[1]