OpenOffice is not a file converter, but you can use it to add a JPG to a document and then export that document as a PDF file. Although it can't open PDF files, OpenOffice can save valid PDF files ...
What is a PDF file? A PDF — or Portable Document Format — file is a type of document that can contain text, illustrations, images, photos, or other types of content. Created by Adobe in 1993, the PDF ...