Comment by Beijinger

#!/bin/bash

# Convert images to PDF

img2pdf *.jpg -o images.pdf

# Merge PDFs

pdfunite file1.pdf file2.pdf images.pdf merged.pdf

# Compress

gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook \ -dNOPAUSE -dQUIET -dBATCH -sOutputFile=compressed.pdf merged.pdf

# Remove unwanted pages (e.g., page 3)

pdftk compressed.pdf cat 1-2 4-end output final.pdf

# Add page numbers

pdfjam final.pdf --outfile final_numbered.pdf --pagecommand '{}' --landscape