Title from file name while retaining cover

Sorry if this a duplicate post, I tried to find a solution via the threads but guess I'm not using the right search terms, if one already exists.

What I want to do is have Calibre take the title of a file from the source, while getting the cover (if one exists) from the content. I tried changing the way Calibre gets the name from the source file in preferences, but this also took away the covers which were already present. Is there any way to do this? I'm converting several types of formats...epub, pdf, cbr.

Thanks!