9 Replies Latest reply on Feb 8, 2018 10:01 AM by renatom83808386

    Form XObject containing Image XObject causes 'Other elements alternate text - Failed'

    renatom83808386 Level 1


      Say we have a PDF with one page whose /Resources dictionary contains the /XObject dictionary referring to a Form XObject. Both the page's and the Form XObject's streams contain a marked content sequence. Sure, the Form XObject has its own StructParents (plural) key.

      Every marked sequence of the Form XObject's content is referred to by structure elements via /MRC (PDF Specification paragraph


      For the Adobe Acrobat Accessibility Full Check everything is fine as long as:

      • the page's content contains some text (Tj);
      • the page's content consumes some Image XObject (Do);
      • the Form XObject's content contains some text (Tj);
      • the Form XObject's content consumes some other Form XObject (Do), in turn containing only some text (Tj).


      Instead if the Form XObject's content consumes some other Image XObject (Do), the Full Check complains that such images are not properly tagged ('Other elements alternate text - Failed').

      Instead the PAC3 Checker is happy.


      Curiously, asking Adobe Acrobat to tag such images does nothing.

      Please, consider that in my case extracting the Form XObject's content to put in directly in the page's content is not an option.


      Considering the mismatch between the Adobe Full Check and PAC3, I need help to understand if the Adobe Full Check is right or not.


      Thank you all.