Python PDF 加水印

Python PDF 加水印

from PyPDF2 import PdfWriter,PdfReader
from reportlab.lib.units import cm
from reportlab.pdfgen import canvas
import reportlab.pdfbase.ttfonts
from reportlab.pdfbase import pdfmetrics
import os

basedir=os.path.dirname(os.path.abspath(__file__))


def create_watermark(content):
    """水印信息"""
    # 默认大小为21cm*29.7cm
    file_name = os.path.join(basedir,"../../media/mark.pdf")
    c = canvas.Canvas(file_name, pagesize=(30 * cm, 30 * cm))
    # 移动坐标原点(坐标系左下为(0,0))
    c.translate(10 * cm, 5 * cm)
    try:
        # 注册中文字体
        pdfmetrics.registerFont(reportlab.pdfbase.ttfonts.TTFont('yahei', '微软雅黑.ttf'))
        c.setFont('yahei',20)
    except:
        # 设置字体
        c.setFont("Helvetica", 30)
    # 指定描边的颜色
    c.setStrokeColorRGB(0, 1, 0)
    # 指定填充颜色
    c.setFillColorRGB(0, 0, 222,0.2)
    # 旋转45度,坐标系被旋转
    c.rotate(30)
    # 指定填充颜色
    # c.setFillColorRGB(0, 0, 0, 0.1)
    # 设置透明度,1为不透明
    c.setFillAlpha(0.1)
    # 画几个文本,注意坐标系旋转的影响
    for i in range(5):
        for j in range(10):
            a = 10 * (i - 1)
            b = 5 * (j - 2)
            c.drawString(a * cm, b * cm, content)
            c.setFillAlpha(0.1)
    # 关闭并保存pdf文件
    c.save()
    return file_name

def add_watermark(pdf_file_in, pdf_file_mark, pdf_file_out):
    """把水印添加到pdf中"""
    pdf_output = PdfWriter()
    input_stream = open(pdf_file_in, 'rb')
    pdf_input = PdfReader(input_stream, strict=False)

    # 获取PDF文件的页数
    pageNum = len(pdf_input.pages)

    # 读入水印pdf文件
    pdf_watermark = PdfReader(open(pdf_file_mark, 'rb'), strict=False)
    # 给每一页打水印
    for i in range(pageNum):
        page = pdf_input.pages[i]
        page.merge_page(pdf_watermark.pages[0])
        page.compress_content_streams()  # 压缩内容
        pdf_output.add_page(page)
    pdf_output.write(open(pdf_file_out, 'wb'))