code: def test_dpi_not_credible(caplog, baiona, outdir, no_outpdf):
      im = baiona
      assert "dpi" not in im.info
      input_image = outdir / "baiona_no_dpi.png"
      im.save(input_image, dpi=(30, 30))
  
      rc = run_ocrmypdf_api(input_image, no_outpdf)
      assert rc == ocrmypdf.ExitCode.input_file
      assert "not credible" in caplog.text
  
file_path: OCRmyPDF/tests/test_image_input.py
imports: from __future__ import annotations
  from unittest.mock import patch
  import img2pdf
  import pikepdf
  import pytest
  from PIL import Image
  import ocrmypdf
  from .conftest import check_ocrmypdf, run_ocrmypdf_api
label_desc: Use image node_id 4 for calling a global function with example usage: test_dpi_not_credible(caplog, baiona, outdir, no_outpdf) without return types