Python add watermark to pdf files

Question

I wrote code to add watermark to pdf files however, the resulting files do not contain the watermark.

import os
import io
from PyPDF2 import PdfReader, PdfWriter
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas

folder_path = 'D:/pdf/input/'
output_folder = 'D:/pdf/output/'
image_path = 'D:/pdf/watermark.jpg'
x, y = 50, 50
page_number = 1

if not os.path.exists(output_folder):
    os.makedirs(output_folder)

for pdf_file in os.listdir(folder_path):
    if pdf_file.endswith(".pdf"):
        pdf_reader = PdfReader(open(os.path.join(folder_path, pdf_file), "rb"))
        pdf_writer = PdfWriter()

        for page_num in range(len(pdf_reader.pages)):
            pdf_page = pdf_reader.pages[page_num]
            pdf_writer.add_page(pdf_page)

            if page_num == page_number - 1:
                packet = io.BytesIO()
                can = canvas.Canvas(packet, pagesize=letter)
                can.drawImage(image_path, x, y)
                can.save()
                packet.seek(0)
                new_pdf = PdfReader(packet)
                pdf_page.merge_page(new_pdf.pages[0])
        
        with open(os.path.join(output_folder, pdf_file), "wb") as output_file:
            pdf_writer.write(output_file)

print("Image added to the specified page of all pdf files and saved in the output folder.")

I've tried changing the image position and page number, but still no effect. I expect watermark to be added at a specific place in the pdf file.

Why do you add the page to the writer before you add the watermark? — Tim Roberts, Jan 17 '23 at 19:22

score 0 · Answer 1 · answered Jan 17 '23 at 22:02

FIXED

import os
import io
from PyPDF2 import PdfReader, PdfWriter
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas

folder_path = 'D:/pdf/pliki/'
output_folder = 'D:/pdf/output/'
sign_path = 'D:/pdf/obraz/podpis.png'

x_position = 300
y_position = 260
width =  150
height = 150

if not os.path.exists(output_folder):
    os.makedirs(output_folder)

packet = io.BytesIO()
can = canvas.Canvas(packet, pagesize=letter)
can.drawImage(sign_path, x_position, y_position, width, height, [112,113,112,113,112,113])
can.save()
packet.seek(0)
new_pdf = PdfReader(packet)

for pdf_file in os.listdir(folder_path):
    if pdf_file.endswith(".pdf"):
        pdf_reader = PdfReader(open(os.path.join(folder_path, pdf_file), "rb"))
        pdf_merged = pdf_reader.pages[0]
        pdf_merged.merge_page(new_pdf.pages[0])
        pdf_writer = PdfWriter()
        
        for i in range(len(pdf_reader.pages)):
            if i == 0:
                pdf_writer.add_page(pdf_merged)
            else:
                pdf_writer.add_page(pdf_reader.pages[i])

                     
        with open(os.path.join(output_folder, pdf_file), "wb") as output_file:
            pdf_writer.write(output_file)

print("Watermark added to the specified page of all pdf files and saved in the output folder.")

Python add watermark to pdf files

1 Answers1