python印章生成

利用pyton的PIL，可以很容易的实现印章生成。

但这里细节比较多，例如姓名字数、透明度、噪点、模糊、纹理、旋转角度等等，如果都想齐全了，还得花费一番功夫。
这里记录一下算法的过程，主要过程就是

1. 生成要印的四个字
2. 绘制圆角矩形
3. 在四个位置上绘用魏碑字体绘制四个字
4. 用纹理图片上随机截取的片段，来给印章添加纹理
5. 用高斯模糊，让印章更加真实
6. 在word模板里，更改模板印章的透明度设置，这样后面更改图片后，印章能获得合适的透明度。

个人印章 个人印章

from random import randint

from PIL import Image, ImageDraw, ImageFont, ImageFilter
from django.conf import settings
from django.core.exceptions import ValidationError
from django.db import models

def validate_leader(strs):
    if len(strs) < 2 or len(strs) > 4:
        raise ValidationError(u'姓名长度2~4个中文')

    for _char in strs:
        if not '\u4e00' <= _char <= '\u9fa5':
            raise ValidationError(u'姓名只能为中文')


def seal_cover_path(instance, filename):
    return f"human/seal/{instance.id}.png"


class Leave(models.Model):
leader = models.CharField('申报人', max_length=4, validators=[validate_leader, ])
stamp = models.ImageField(verbose_name='呈报人印章', null=True, blank=True, upload_to=seal_cover_path)
    
    def getChars(self):
        if len(self.leader) == 2:
            chars = self.leader + '之印'
        elif len(self.leader) == 3:
            chars = self.leader + '印'
        else:
            chars = self.leader
        return chars

    def generate_stamp(self):
        """ 生成印章算法 """
        img = Image.new("RGBA", (200, 200), (255, 255, 255, 0))
        draw = ImageDraw.Draw(img)
        draw.rounded_rectangle(((0, 0), (200, 200)), 16, outline='red', width=8)

        chars = self.getChars()
        font = ImageFont.truetype("C:/Windows/Fonts/STXINWEI.TTF", 92, encoding="utf-8")
        draw.text((98, 8), chars[0], fill='red', font=font)
        draw.text((98, 98), chars[1], fill='red', font=font)
        draw.text((2, 8), chars[2], fill='red', font=font)
        draw.text((2, 98), chars[3], fill='red', font=font)

        wl_path = settings.BASE_DIR / 'human/wl.jpg'

        img_wl = Image.open(wl_path)
        pos_random = (randint(100, 200), randint(120, 200))
        box = (pos_random[0], pos_random[1], pos_random[0] + 400, pos_random[1] + 200)
        img_wl_random = img_wl.crop(box)
        img_wl_random = img_wl_random.resize(img.size).convert('L').filter(ImageFilter.GaussianBlur(1))

        X, Y = img.size
        for x in range(X):
            for y in range(Y):
                dot = (x, y)
                img.putpixel(dot,
                             img.getpixel(dot)[:3] + (int(img_wl_random.getpixel(dot) / 255 * img.getpixel(dot)[3]),))
        # 进行一次高斯模糊，提高真实度
        self.img = img.filter(ImageFilter.GaussianBlur(0.6))

        relative_path = seal_cover_path(self, '')
        filename = settings.MEDIA_ROOT / relative_path
        if not filename.parent.exists():
            filename.parent.mkdir(parents=True, exist_ok=True)

        filename = str(filename)
        img.save(filename)
        self.stamp.name = relative_path
        self.save()
        

    def save(self, *args, **kwargs):
        """ 需要完成印章生成"""
        self.leader = self.leader.replace(' ', '')
        super(Leave, self).save(*args, **kwargs)
        # 放到后面，这样才有id
        if not self.stamp.name:
            self.generate_stamp()

wl.jpg