remove unused objects

Hi Jake,

you can remove a known unused image for example but there isn't a more automatic function for this.
To remove an unsused object you should use the free cmd-tool PDFtk.

Here's a description how to do it from our member "chicks".
It's ober 13 years old but should still work:

1. Uncompress the original PDF using pdftk:
    pdftk png_example.pdf output step1.pdf uncompress

2. Edit step1.pdf (using commandline edit.exe):
    Find the object of interest, in this case 5 0 obj.
    Remove all references to this object by deleting the
    lines associated with it, including:
      /XOBJ7BC610 5 0 R
      /XOBJ7BC610 Do
      Everything between the line starting with 5 0 obj
      and endobj
    Save the edited file to step2.pdf.

3. The xref table in step2.pdf is now corrupt, so we need to fix it. We'll also recompress the PDF:

    pdftk step2.pdf output step3.pdf compress