I'm using latexdiff to show changes that I make in a large text (200+ pages). Most of my changes affect only a few pages though, so I don't want my readers to sift through 200 pages looking for the rare pages where isolated typo corrections were made: only about 30pp out of the 200 will contain changes. I would like to: Insert hidden PDF markers…

modified_latexdiff_header.tex

\RequirePackage[normalem]{ulem}
\RequirePackage{color}
\definecolor{RED}{rgb}{1,0,0}
\definecolor{BLUE}{rgb}{0,0,1}
%% modif start
  \usepackage{pdfcomment}
  \providecommand{\DIFadd}[1]{\pdfmargincomment[opacity=0.0]{DIFFCHANGE}{\protect\color{blue}\uwave{#1}}}
  \providecommand{\DIFdel}[1]{\pdfmargincomment[opacity=0.0]{DIFFCHANGE}{\protect\color{red}\sout{#1}}}
%% modifs end
\providecommand{\DIFaddbegin}{}
\providecommand{\DIFaddend}{}
\providecommand{\DIFdelbegin}{}
\providecommand{\DIFdelend}{}
\providecommand{\DIFaddFL}[1]{\DIFadd{#1}}
\providecommand{\DIFdelFL}[1]{\DIFdel{#1}}
\providecommand{\DIFaddbeginFL}{}
\providecommand{\DIFaddendFL}{}
\providecommand{\DIFdelbeginFL}{}
\providecommand{\DIFdelendFL}{}
\begin{document}

selectdiffpages.py

# Setup and params
############################################
INFILENAME = "diff.pdf"         # Input PDF filename
OUTFILENAME = "diff_subset.pdf"    # Output PDF filename
pages_with_changes = set()      # List of pages to select


# Find pages with DIFFCHANGE annotations on them
################################################
from pdfminer.pdfparser import PDFParser
from pdfminer.pdfdocument import PDFDocument
from pdfminer.pdfpage import PDFPage
from pdfminer.pdfinterp import PDFResourceManager, PDFPageInterpreter
from pdfminer.pdfdevice import PDFDevice
from pdfminer.layout import LAParams
from pdfminer.converter import PDFPageAggregator

# Open file
infp = open(INFILENAME, 'rb')
print "Opened " + INFILENAME + " for reading"

# Create a PDF parser object associated with the file object.
parser = PDFParser(infp)

# Create a PDF document object that stores the document structure.
document = PDFDocument(parser)

# Create a PDF resource manager object that stores shared resources.
rsrcmgr = PDFResourceManager()

# Set parameters for analysis.
laparams = LAParams()

# Create a PDF page aggregator object.
device = PDFPageAggregator(rsrcmgr, laparams=laparams)

# Create a PDF interpreter object.
interpreter = PDFPageInterpreter(rsrcmgr, device)

pages_gen = PDFPage.create_pages(document)

for pgnum, page in enumerate(pages_gen):
    #print "processing page " + str(pgnum+1)
    if page.annots:
        for a in page.annots:
            a = a.resolve()
            if a['Type'].name == 'Annot' and a['Subtype'].name == 'Text':
                if a["Contents"]  == 'DIFFCHANGE':
                    pages_with_changes.add(pgnum)
                    #print "page " + str(pgnum+1) + " contains changes"
infp.close()

print "The following pages have changes in them:"
print sorted( list(pages_with_changes) )

# Write out subset
############################################
import sys
import os
from pdfrw import PdfReader, PdfWriter

pages = PdfReader(INFILENAME).pages
outdata = PdfWriter()
for pagenum in sorted( list(pages_with_changes) ):
    outdata.addpage(pages[pagenum])
outdata.write(OUTFILENAME)

print "Wrote output to " + OUTFILENAME