"The impression left in the prior message that the *.ftmb file is compressed is not true. The backup file is not compressed and takes as much space as the old ftm file plus images take."
Oh dear, there must be an installation problem on my computer (XP SP3, FTM2012 all updates). The .ftmb is a zip format file containing a .ftm file and folder with all the associated media files.
Add .zip to the filename end and open with 7zip. One of the .ftmbs shows the .ftm as 29Mb uncompressed, 6Mb compressed.
Media files are generally already compressed if .jpgs.
If you transfer as a .ftmb file then all the necessary media files, no matter where they've been hidden, will move across as well and be restored in the media folder.