Chen Xiao
@@ -0,0 +1,249 @@
|
||||
# coding: utf-8
|
||||
"""
|
||||
captcha.image
|
||||
~~~~~~~~~~~~~
|
||||
|
||||
Generate Image CAPTCHAs, just the normal image CAPTCHAs you are using.
|
||||
"""
|
||||
|
||||
from __future__ import annotations
|
||||
import os
|
||||
import secrets
|
||||
import typing as t
|
||||
from PIL.Image import new as createImage, Image, Transform, Resampling
|
||||
from PIL.ImageDraw import Draw, ImageDraw
|
||||
from PIL.ImageFilter import SMOOTH
|
||||
from PIL.ImageFont import FreeTypeFont, truetype
|
||||
from io import BytesIO
|
||||
|
||||
__all__ = ['ImageCaptcha']
|
||||
|
||||
|
||||
ColorTuple = t.Union[t.Tuple[int, int, int], t.Tuple[int, int, int, int]]
|
||||
|
||||
DATA_DIR = os.path.join(os.path.abspath(os.path.dirname(__file__)), 'data')
|
||||
DEFAULT_FONTS = [os.path.join(DATA_DIR, 'DroidSansMono.ttf')]
|
||||
|
||||
|
||||
class ImageCaptcha:
|
||||
"""Create an image CAPTCHA.
|
||||
|
||||
Many of the codes are borrowed from wheezy.captcha, with a modification
|
||||
for memory and developer friendly.
|
||||
|
||||
ImageCaptcha has one built-in font, DroidSansMono, which is licensed under
|
||||
Apache License 2. You should always use your own fonts::
|
||||
|
||||
captcha = ImageCaptcha(fonts=['/path/to/A.ttf', '/path/to/B.ttf'])
|
||||
|
||||
You can put as many fonts as you like. But be aware of your memory, all of
|
||||
the fonts are loaded into your memory, so keep them a lot, but not too
|
||||
many.
|
||||
|
||||
:param width: The width of the CAPTCHA image.
|
||||
:param height: The height of the CAPTCHA image.
|
||||
:param fonts: Fonts to be used to generate CAPTCHA images.
|
||||
:param font_sizes: Random choose a font size from this parameters.
|
||||
"""
|
||||
lookup_table: list[int] = [int(i * 1.97) for i in range(256)]
|
||||
character_offset_dx: tuple[int, int] = (0, 4)
|
||||
character_offset_dy: tuple[int, int] = (0, 6)
|
||||
character_rotate: tuple[int, int] = (-30, 30)
|
||||
character_warp_dx: tuple[float, float] = (0.1, 0.3)
|
||||
character_warp_dy: tuple[float, float] = (0.2, 0.3)
|
||||
word_space_probability: float = 0.5
|
||||
word_offset_dx: float = 0.25
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
width: int = 160,
|
||||
height: int = 60,
|
||||
fonts: list[str] | None = None,
|
||||
font_sizes: tuple[int, ...] | None = None):
|
||||
self._width = width
|
||||
self._height = height
|
||||
self._fonts = fonts or DEFAULT_FONTS
|
||||
self._font_sizes = font_sizes or (42, 50, 56)
|
||||
self._truefonts: list[FreeTypeFont] = []
|
||||
|
||||
@property
|
||||
def truefonts(self) -> list[FreeTypeFont]:
|
||||
if self._truefonts:
|
||||
return self._truefonts
|
||||
self._truefonts = [
|
||||
truetype(n, s)
|
||||
for n in self._fonts
|
||||
for s in self._font_sizes
|
||||
]
|
||||
return self._truefonts
|
||||
|
||||
@staticmethod
|
||||
def create_noise_curve(image: Image, color: ColorTuple) -> Image:
|
||||
w, h = image.size
|
||||
x1 = secrets.randbelow(int(w / 5) + 1)
|
||||
x2 = secrets.randbelow(w - int(w / 5) + 1) + int(w / 5)
|
||||
y1 = secrets.randbelow(h - 2 * int(h / 5) + 1) + int(h / 5)
|
||||
y2 = secrets.randbelow(h - y1 - int(h / 5) + 1) + y1
|
||||
points = [x1, y1, x2, y2]
|
||||
end = secrets.randbelow(41) + 160
|
||||
start = secrets.randbelow(21)
|
||||
Draw(image).arc(points, start, end, fill=color)
|
||||
return image
|
||||
|
||||
@staticmethod
|
||||
def create_noise_dots(
|
||||
image: Image,
|
||||
color: ColorTuple,
|
||||
width: int = 3,
|
||||
number: int = 30) -> Image:
|
||||
draw = Draw(image)
|
||||
w, h = image.size
|
||||
while number:
|
||||
x1 = secrets.randbelow(w + 1)
|
||||
y1 = secrets.randbelow(h + 1)
|
||||
draw.line(((x1, y1), (x1 - 1, y1 - 1)), fill=color, width=width)
|
||||
number -= 1
|
||||
return image
|
||||
|
||||
def _draw_character(
|
||||
self,
|
||||
c: str,
|
||||
draw: ImageDraw,
|
||||
color: ColorTuple) -> Image:
|
||||
font = secrets.choice(self.truefonts)
|
||||
_, _, w, h = draw.multiline_textbbox((1, 1), c, font=font)
|
||||
|
||||
dx1 = secrets.randbelow(self.character_offset_dx[1] - self.character_offset_dx[0] + 1) + self.character_offset_dx[0]
|
||||
dy1 = secrets.randbelow(self.character_offset_dy[1] - self.character_offset_dy[0] + 1) + self.character_offset_dy[0]
|
||||
im = createImage('RGBA', (int(w) + dx1, int(h) + dy1))
|
||||
Draw(im).text((dx1, dy1), c, font=font, fill=color)
|
||||
|
||||
# rotate
|
||||
im = im.crop(im.getbbox())
|
||||
im = im.rotate(
|
||||
self.character_rotate[0] + (secrets.randbits(32) / (2**32)) * (self.character_rotate[1] - self.character_rotate[0]),
|
||||
Resampling.BILINEAR,
|
||||
expand=True,
|
||||
)
|
||||
|
||||
# warp
|
||||
dx2 = w * (secrets.randbits(32) / (2**32)) * (self.character_warp_dx[1] - self.character_warp_dx[0]) + self.character_warp_dx[0]
|
||||
dy2 = h * (secrets.randbits(32) / (2**32)) * (self.character_warp_dy[1] - self.character_warp_dy[0]) + self.character_warp_dy[0]
|
||||
x1 = int(secrets.randbits(32) / (2**32) * (dx2 - (-dx2)) + (-dx2))
|
||||
y1 = int(secrets.randbits(32) / (2**32) * (dy2 - (-dy2)) + (-dy2))
|
||||
x2 = int(secrets.randbits(32) / (2**32) * (dx2 - (-dx2)) + (-dx2))
|
||||
y2 = int(secrets.randbits(32) / (2**32) * (dy2 - (-dy2)) + (-dy2))
|
||||
w2 = w + abs(x1) + abs(x2)
|
||||
h2 = h + abs(y1) + abs(y2)
|
||||
data = (
|
||||
x1, y1,
|
||||
-x1, h2 - y2,
|
||||
w2 + x2, h2 + y2,
|
||||
w2 - x2, -y1,
|
||||
)
|
||||
im = im.resize((w2, h2))
|
||||
im = im.transform((int(w), int(h)), Transform.QUAD, data)
|
||||
return im
|
||||
|
||||
def create_captcha_image(
|
||||
self,
|
||||
chars: str,
|
||||
color: ColorTuple,
|
||||
background: ColorTuple) -> Image:
|
||||
"""Create the CAPTCHA image itself.
|
||||
|
||||
:param chars: text to be generated.
|
||||
:param color: color of the text.
|
||||
:param background: color of the background.
|
||||
|
||||
The color should be a tuple of 3 numbers, such as (0, 255, 255).
|
||||
"""
|
||||
image = createImage('RGB', (self._width, self._height), background)
|
||||
draw = Draw(image)
|
||||
|
||||
images: list[Image] = []
|
||||
for c in chars:
|
||||
if secrets.randbits(32) / (2**32) > self.word_space_probability:
|
||||
images.append(self._draw_character(" ", draw, color))
|
||||
images.append(self._draw_character(c, draw, color))
|
||||
|
||||
text_width = sum([im.size[0] for im in images])
|
||||
|
||||
width = max(text_width, self._width)
|
||||
image = image.resize((width, self._height))
|
||||
|
||||
average = int(text_width / len(chars))
|
||||
rand = int(self.word_offset_dx * average)
|
||||
offset = int(average * 0.1)
|
||||
|
||||
for im in images:
|
||||
w, h = im.size
|
||||
mask = im.convert('L').point(self.lookup_table)
|
||||
image.paste(im, (offset, int((self._height - h) / 2)), mask)
|
||||
offset = offset + w + (-secrets.randbelow(rand + 1))
|
||||
|
||||
if width > self._width:
|
||||
image = image.resize((self._width, self._height))
|
||||
|
||||
return image
|
||||
|
||||
def generate_image(self, chars: str,
|
||||
bg_color: ColorTuple | None = None,
|
||||
fg_color: ColorTuple | None = None) -> Image:
|
||||
"""Generate the image of the given characters.
|
||||
|
||||
:param chars: text to be generated.
|
||||
:param bg_color: background color of the image in rgb format (r, g, b).
|
||||
:param fg_color: foreground color of the text in rgba format (r,g,b,a).
|
||||
"""
|
||||
background = bg_color if bg_color else random_color(238, 255)
|
||||
random_fg_color = random_color(10, 200, secrets.randbelow(36) + 220)
|
||||
color: ColorTuple = fg_color if fg_color else random_fg_color
|
||||
|
||||
im = self.create_captcha_image(chars, color, background)
|
||||
self.create_noise_dots(im, color)
|
||||
self.create_noise_curve(im, color)
|
||||
im = im.filter(SMOOTH)
|
||||
return im
|
||||
|
||||
def generate(self, chars: str, format: str = 'png',
|
||||
bg_color: ColorTuple | None = None,
|
||||
fg_color: ColorTuple | None = None) -> BytesIO:
|
||||
"""Generate an Image Captcha of the given characters.
|
||||
|
||||
:param chars: text to be generated.
|
||||
:param format: image file format
|
||||
:param bg_color: background color of the image in rgb format (r, g, b).
|
||||
:param fg_color: foreground color of the text in rgba format (r,g,b,a).
|
||||
"""
|
||||
im = self.generate_image(chars, bg_color=bg_color, fg_color=fg_color)
|
||||
out = BytesIO()
|
||||
im.save(out, format=format)
|
||||
out.seek(0)
|
||||
return out
|
||||
|
||||
def write(self, chars: str, output: str, format: str = 'png',
|
||||
bg_color: ColorTuple | None = None,
|
||||
fg_color: ColorTuple | None = None) -> None:
|
||||
"""Generate and write an image CAPTCHA data to the output.
|
||||
|
||||
:param chars: text to be generated.
|
||||
:param output: output destination.
|
||||
:param format: image file format
|
||||
:param bg_color: background color of the image in rgb format (r, g, b).
|
||||
:param fg_color: foreground color of the text in rgba format (r,g,b,a).
|
||||
"""
|
||||
im = self.generate_image(chars, bg_color=bg_color, fg_color=fg_color)
|
||||
im.save(output, format=format)
|
||||
|
||||
|
||||
def random_color(
|
||||
start: int,
|
||||
end: int,
|
||||
opacity: int | None = None) -> ColorTuple:
|
||||
red = secrets.randbelow(end - start + 1) + start
|
||||
green = secrets.randbelow(end - start + 1) + start
|
||||
blue = secrets.randbelow(end - start + 1) + start
|
||||
if opacity is None:
|
||||
return red, green, blue
|
||||
return red, green, blue, opacity
|
||||
Reference in New Issue
Block a user