关于python：使用PyPDF2在PDF上去除水印


Watermark Removal on PDF with PyPDF2

This Section imports the necessary classes from the PyPDF2 library

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from PyPDF2 import PdfFileReader, PdfFileWriter
from PyPDF2.pdf import ContentStream
from PyPDF2.generic import TextStringObject, NameObject
from PyPDF2.utils import b_

>The watermark says SAMPLE on it so I've tried different capitalization cases
wm_text = 'Sample'
replace_with = ''
>I'm hoping to just replace the SAMPLE watermark with nothing so a space could suffice

> Load PDF into pyPDF
source = PdfFileReader(open('input.pdf',"rb"))
output = PdfFileWriter()

> For each page
for page in range(source.getNumPages()):
    # Get the current page and it's contents
    page = source.getPage(page)
    content_object = page["/Contents"].getObject()
    content = ContentStream(content_object, source)

> Loop over all pdf elements
    for operands, operator in content.operations:

Was told to adapt this part dependent on my PDF file

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        if operator == b_("TJ"):
            text = operands[0][0]
            if isinstance(text, TextStringObject) and text.startswith(wm_text):
                operands[0] = TextStringObject(replace_with)

Set the modified content as content object on the page

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    page.__setitem__(NameObject('/Contents'), content)

Add the page to the output

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    output.addPage(page)

写流
outputStream = open(" output.pdf"，" wb")
output.write(outputStream)

在这里使用问题中的代码是在Python 3中可以使用的函数。

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def remove_watermark(wm_text, inputFile, outputFile):
    from PyPDF4 import PdfFileReader, PdfFileWriter
    from PyPDF4.pdf import ContentStream
    from PyPDF4.generic import TextStringObject, NameObject
    from PyPDF4.utils import b_
   
    with open(inputFile,"rb") as f:
        source = PdfFileReader(f,"rb")
        output = PdfFileWriter()

        for page in range(source.getNumPages()):
            page = source.getPage(page)
            content_object = page["/Contents"].getObject()
            content = ContentStream(content_object, source)

            for operands, operator in content.operations:
                if operator == b_("Tj"):
                    text = operands[0]

                    if isinstance(text, str) and text.startswith(wm_text):
                        operands[0] = TextStringObject('')

            page.__setitem__(NameObject('/Contents'), content)
            output.addPage(page)

        with open(outputFile,"wb") as outputStream:
            output.write(outputStream)
           
wm_text = 'wm_text'
inputFile = r'input.pdf'
outputFile = r"output.pdf"
remove_watermark(wm_text, inputFile, outputFile)
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