Python实现给PDF添加水印的方法

pip install PyPDF2

// =============================================
# @Time  : 2021-01-24
# @Author : AXYZdong
# @CSDN  : https://axyzdong.blog.csdn.net/
# @FileName: PDFset.py
# @Software: Python IDE
// =============================================
from PyPDF2 import PdfFileReader, PdfFileWriter

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

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

  # 读入水印pdf文件
  pdf_watermark = PdfFileReader(open(pdf_file_mark, 'rb'), strict=False)
  # 给每一页打水印
  for i in range(pageNum):
    page = pdf_input.getPage(i)
    page.mergePage(pdf_watermark.getPage(0))
    page.compressContentStreams() # 压缩内容
    pdf_output.addPage(page)
  pdf_output.write(open(pdf_file_out, 'wb'))

if __name__ == '__main__':
  pdf_file_in = '基于matlab的控制系统与仿真-1_AXYZdong的博客-CSDN博客.pdf'
  pdf_file_out = 'watermarked.pdf'
  pdf_file_mark = 'watermark.pdf'
  add_watermark(pdf_file_in, pdf_file_mark, pdf_file_out)
  

// =============================================
# @Time  : 2021-01-24
# @Author : AXYZdong
# @CSDN  : https://axyzdong.blog.csdn.net/
# @FileName: PDFSet.py
# @Software: Python IDE
// =============================================
from PyPDF2 import PdfFileReader, PdfFileWriter
from reportlab.lib.units import cm
from reportlab.pdfgen import canvas


def create_watermark(content):
  """水印信息"""
  # 默认大小为21cm*29.7cm
  file_name = "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)

  # 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, 1, 0)
  # 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 = PdfFileWriter()
  input_stream = open(pdf_file_in, 'rb')
  pdf_input = PdfFileReader(input_stream, strict=False)

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

  # 读入水印pdf文件
  pdf_watermark = PdfFileReader(open(pdf_file_mark, 'rb'), strict=False)
  # 给每一页打水印
  for i in range(pageNum):
    page = pdf_input.getPage(i)
    page.mergePage(pdf_watermark.getPage(0))
    page.compressContentStreams() # 压缩内容
    pdf_output.addPage(page)
  pdf_output.write(open(pdf_file_out, 'wb'))

if __name__ == '__main__':
  pdf_file_in = '基于matlab的控制系统与仿真-1_AXYZdong的博客-CSDN博客.pdf'
  pdf_file_out = 'watermarked.pdf'
  pdf_file_mark = create_watermark('CSDN@AXYZdong')
  add_watermark(pdf_file_in, pdf_file_mark, pdf_file_out)