Apache OpenOffice (AOO) Bugzilla – Issue 122965
ACCESSIBILITY: Impress PDF export loses image Title and Description
Last modified: 2013-08-12 09:12:17 UTC
Images in Impress lose their text alternatives when a presentation is exported as PDF. Images inserted in presentations can have a Title and Description ("text alternatives"). This is an accessibility requirement for users of screen readers (blind users) and for exporting to non-visual formats such as audio books (e.g. in DAISY format) and Braille. To reproduce the issue, follow these steps: 1. Create a presentation in Impress; add a picture to a slide. 2. Right-click on the picture and select Description from the context menu. 3. Add a short description in the Title field and a longer description in the Description field. 4. Save the presentation; then export it as PDF. In the PDF Options dialog, check at least "Tagged PDF" (the PDF is mostly inaccessible without those tags). 5. Open the resulting PDF file in a program that allows you to check the accessibility of the PDF, e.g. Acobe Acrobat Pro (Adobe Reader can only check whether PDF is tagged or not, it can't perform a full accessibility evaluation), the free PDF Accessibility Checker (PAC) by access-for-all.ch, or the online PDF checker at http://accessibility.egovmon.no/en/pdfcheck/. The accessibility report will say that an image is missing a text alternative. Notes: 1. Writer does not lose text alternatives on images when exporting to PDF. 2. You can go through the above steps using three variations: give the image only a title, give the image only a description, give the image both a title and a description. In each of these cases, the images in the PDF file will have no text alternative.
@Christophe, do you know if this was working previously, in 3.4.1?
I have been warning both OpenOffice users and LibreOffice users about this bug for at least two years now, so it's definitely not new. I rechecked it with Apache OpenOffice 3.4.0 (I don't have 3.4.1 available right now), and the bug is also present in that version.
Some background info from OASIS Open Document Format Version 1.2 Part 1: 10.3.17 <svg:title> The <svg:title> element specifies a name for a graphic object. (...) 10.3.18 <svg:desc> The <svg:desc> element specifies a prose description of a graphic object that may be used to support accessibility. See appendix D. (...) From Appendix D, section D.1 "When transforming from another document format to OpenDocument the short names, like HTML's alt text on the <img> elements shall be mapped to the <svg:title> element." So <svg:title> is the text alternative that should always be present if the image is not purely decorative. (See also section D.1.1 in Appendix D: "Authors should not assign names to objects having no semantic value.")
adjusting field Version as the defect has been reported also for previous versions.