4. python 验证码
python 生成验证码
备注
需要使用3种font字体，Arial.ttf, Georgia.ttf, actionj.ttf
import base64
import os.path
import random
import string
import typing as t
from io import BytesIO
from PIL import Image
from PIL import ImageFilter
from PIL.ImageDraw import Draw
from PIL.ImageFont import truetype
class Bezier:
def __init__(self):
self.sequence = tuple([num / 20.0 for num in range(21)])
self.beziers = {}
@classmethod
def pascal_row(cls, n):
""" Returns n-th row of Pascal's triangle
"""
result = [1]
x, numerator = 1, n
for denominator in range(1, n // 2 + 1):
x *= numerator
x /= denominator
result.append(x)
numerator -= 1
if n & 1 == 0:
result.extend(reversed(result[:-1]))
else:
result.extend(reversed(result))
return result
def make_bezier(self, number: int):
"""
生成贝塞尔曲线
:param number: 点数
"""
try:
return self.beziers[number]
except KeyError:
combinations = self.pascal_row(number - 1)
result = []
for num in self.sequence:
tpowers = (num ** i for i in range(number))
upowers = ((1 - num) ** i for i in range(number - 1, -1, -1))
coefs = [c * a * b for c, a, b in zip(combinations,
tpowers, upowers)]
result.append(coefs)
self.beziers[number] = result
return result
class Captcha:
"""
Usages::
name, text, images = captcha.generate_captcha()
"""
def __init__(self):
self._bezier = Bezier()
self._dir = os.path.dirname(__file__)
@staticmethod
def instance():
if not hasattr(Captcha, "_instance"):
Captcha._instance = Captcha()
return Captcha._instance
def initialize(self, width: int = 200, height: int = 75, color: str = None,
fill_text: str = None, fonts: str = None) -> t.NoReturn:
"""
初始化
:param width: 宽度
:param height: 高度
:param color: 颜色
:param fill_text: 文本
:param fonts: 字体
:return:
"""
self._text = fill_text if fill_text else random.sample(
string.ascii_uppercase + string.ascii_uppercase + '3456789', 4
)
self.fonts = fonts if fonts else [
os.path.join(self._dir, 'fonts', font)
for font in ['Arial.ttf', 'Georgia.ttf', 'actionj.ttf']
]
self.width = width
self.height = height
self._color = color if color else self.random_color(
0, 200, random.randint(220, 255)
)
@staticmethod
def random_color(start: int, end: int, opacity: int = None) -> \
t.Union[t.Tuple[int, int, int], t.Tuple[int, int, int, int]]:
"""
生成随机颜色
:param start: 颜色起始数值
:param end: 颜色末尾数值
:param opacity: 透明度
:return: tuple (红、绿、蓝) or (红、绿、蓝, 透明度)
"""
red = random.randint(start, end)
green = random.randint(start, end)
blue = random.randint(start, end)
if opacity is None:
return red, green, blue
return red, green, blue, opacity
def gen_image_background(self, image: Image) -> Image:
"""
设置背景
:param image: Image对象
:return: Image对象
"""
Draw(image).rectangle([(0, 0), image.size],
fill=self.random_color(238, 255))
return image
@classmethod
def gen_image_smooth(cls, image: Image) -> Image:
"""
模糊图像
:param image: Image对象
:return: Image对象
"""
return image.filter(ImageFilter.SMOOTH)
def gen_image_curve(self, image: Image, width: int = 4,
number: int = 6) -> Image:
"""
设置图像曲线
:param image: Image对象
:param width: 宽度
:param number: 点数
:return: image对象
"""
dx, height = image.size
dx /= number
path = [(dx * i, random.randint(0, height))
for i in range(1, number)]
bcoefs = self._bezier.make_bezier(number - 1)
points = []
for coefs in bcoefs:
points.append(tuple(sum([coef * p for coef, p in zip(coefs, ps)])
for ps in zip(*path)))
Draw(image).line(points, fill=self._color, width=width)
return image
def gen_image_noise(self, image: Image, number: int = 50,
level: int = 2) -> Image:
"""
设置图像噪点
:param image: Image对象
:param number: 点数
:param level: 级别
:return: Image对象
"""
width, height = image.size
dx = width / 10
width -= dx
dy = height / 10
height -= dy
draw = Draw(image)
for i in range(number):
x = int(random.uniform(dx, width))
y = int(random.uniform(dy, height))
draw.line(((x, y), (x + level, y)), fill=self._color, width=level)
return image
def gen_image_text(self, image: Image, fonts: t.Iterable,
font_sizes: t.Tuple[int] = None,
drawings: t.Iterable = None,
squeeze_factor: float = 0.75) -> Image:
"""
设置图像文本内容
:param image: Image对象
:param fonts: 字体
:param font_sizes: 字体大小
:param drawings:
:param squeeze_factor:
:return: Image对象
"""
color = self._color
fonts = tuple([truetype(font, size)
for font in fonts
for size in font_sizes or (65, 70, 75)])
draw = Draw(image)
char_images = []
for char in self._text:
font = random.choice(fonts)
char_width, char_height = draw.textsize(char, font=font)
char_image = Image.new('RGB', (char_width, char_height), (0, 0, 0))
char_draw = Draw(char_image)
char_draw.text((0, 0), char, font=font, fill=color)
char_image = char_image.crop(char_image.getbbox())
for drawing in drawings:
draw_obj = getattr(self, drawing)
char_image = draw_obj(char_image)
char_images.append(char_image)
width, height = image.size
offset = int((width - sum(
int(i.size[0] * squeeze_factor) for i in char_images[:-1]
) - char_images[-1].size[0]) / 2)
for char_image in char_images:
char_width, char_height = char_image.size
mask = char_image.convert('L').point(lambda i: i * 1.97)
image.paste(char_image,
(offset, int((height - char_height) / 2)),
mask)
offset += int(char_width * squeeze_factor)
return image
def gen_image(self) -> Image:
"""
生成图像
:return: Image对象
"""
# 创建初始图像
image = Image.new('RGB', (self.width, self.height), (64, 224, 208))
# 设置图像背景
image = self.gen_image_background(image)
# 设置图像文本
image = self.gen_image_text(image, self.fonts,
drawings=['warp', 'rotate', 'offset'])
# 设置图像曲线
image = self.gen_image_curve(image)
# 设置图像噪点
image = self.gen_image_noise(image)
# 模糊图像
image = self.gen_image_smooth(image)
return image
@staticmethod
def warp(image, dx_factor=0.27, dy_factor=0.21):
width, height = image.size
dx = width * dx_factor
dy = height * dy_factor
x1 = int(random.uniform(-dx, dx))
y1 = int(random.uniform(-dy, dy))
x2 = int(random.uniform(-dx, dx))
y2 = int(random.uniform(-dy, dy))
image2 = Image.new('RGB',
(width + abs(x1) + abs(x2),
height + abs(y1) + abs(y2)))
image2.paste(image, (abs(x1), abs(y1)))
width2, height2 = image2.size
return image2.transform(
(width, height), Image.QUAD,
(x1, y1,
-x1, height2 - y2,
width2 + x2, height2 + y2,
width2 - x2, -y1))
@staticmethod
def offset(image, dx_factor=0.1, dy_factor=0.2):
width, height = image.size
dx = int(random.random() * width * dx_factor)
dy = int(random.random() * height * dy_factor)
image2 = Image.new('RGB', (width + dx, height + dy))
image2.paste(image, (dx, dy))
return image2
@staticmethod
def rotate(image, angle=25):
return image.rotate(
random.uniform(-angle, angle), Image.BILINEAR, expand=1)
def captcha(self, path: str = None, fmt: str = 'JPEG'):
"""
创建图片验证码
:param path: 文件保存路径
:param fmt: 图片格式 PNG or JPEG
:return: tuple, (name, text, StringIO.value)
"""
image = self.gen_image()
random_name = "".join(random.sample(
string.ascii_lowercase + string.ascii_uppercase + '3456789', 24))
random_text = "".join(self._text)
out = BytesIO()
image.save(out, format=fmt)
if path:
image.save(os.path.join(path, random_name), fmt)
return random_name, random_text, self.generate_base64(out.getvalue())
def generate_captcha(self) -> t.Tuple[str, str, str]:
"""
生成图片验证码
:return: tuple (StringIO.value, 验证码文本内容、验证码base64编码)
"""
# 初始化
self.initialize()
# 返回验证码
return self.captcha("")
@staticmethod
def generate_base64(image):
base64_data = base64.b64encode(image)
base64_data = 'data:image/bmp;base64,' + base64_data.decode()
return base64_data
captcha = Captcha.instance()