code: def add_options(parser):
      gs = parser.add_argument_group(
          "Ghostscript", "Advanced control of Ghostscript"
      )
      gs.add_argument(
          "--color-conversion-strategy",
          action="store",
          type=str,
          metavar="STRATEGY",
          choices=ghostscript.COLOR_CONVERSION_STRATEGIES,
          default="LeaveColorUnchanged",
          help="Set Ghostscript color conversion strategy",
      )
      gs.add_argument(
          "--pdfa-image-compression",
          choices=["auto", "jpeg", "lossless"],
          default="auto",
          help="Specify how to compress images in the output PDF/A. 'auto' lets "
          "OCRmyPDF decide.  'jpeg' changes all grayscale and color images to "
          "JPEG compression.  'lossless' uses PNG-style lossless compression "
          "for all images.  Monochrome images are always compressed using a "
          "lossless codec.  Compression settings "
          "are applied to all pages, including those for which OCR was "
          "skipped.  Not supported for --output-type=pdf ; that setting "
          "preserves the original compression of all images.",
      )
  
file_path: OCRmyPDF/src/ocrmypdf/builtin_plugins/ghostscript.py
imports: from __future__ import annotations
  import logging
  from packaging.version import Version
  from ocrmypdf import hookimpl
  from ocrmypdf._exec import ghostscript
  from ocrmypdf.exceptions import MissingDependencyError
  from ocrmypdf.subprocess import check_external_program
label_desc: Use image node_id 1 for calling a global function with example usage: add_options(parser) without return types