Created attachment 54147 [details]
Two slides: one containing images without a name, one containing images with a name

When exporting ODP from Impress to the Microsoft PowerPoint format PPTX the title (a text alternative for accessibility) on images is lost.

Steps to reproduced the issue:
1. Create a new presentation in Impress.
2. Add an image and give it only a title (right-click, choose "Description" from the context menu and fill in "Title").
3. Add an image and give it only a description (right-click, choose "Description" and fill in "Description").
4. Add an image and give it both a title and a description (right-click, choose "Description" and fill in both fields in the dialog window).
5. Save the file as "Microsoft PowerPoint 2007/2010 XML (.pptx)".
6. Open the PPTX file in Microsoft PowerPoint 2010 (or an older version that supports PPTX), right-click on each image, choose "Format picture", then "Alt text": the Title field is empty (while the Description field is preserved).

Note: you can give images a name (so they become visible in the Navigator), but this does not make a difference.

Desired behaviour:
When exporting to PPTX, ODF's title and description should be mapped to
DOCX's title and description.