I hadn't misunderstood your request,.There is no process available in VBA to do what you actually stated that you require. I simply pointed out a method that is as close as you are likely to get to recover the original format of the images.
However, some years ago, Stephan Lebans produced a function for older DOC format documents some time ago that would save a selected image as BMP format. This is not the same as the original image, but a facsimile of it that may fulfil your requirements.
The document containing the code is available in a zip file linked from
http://www.lebans.com/msword.htm. The document in the zip can be opened in current Word versions and when saved as DOTM format, still appears to work with XML format document images.
Paul has pointed out the pitfalls of targetting the images. If you can overcome that then you may be able to loop through the images and process them using the macro function. I guess it rather depends on whether BMP is an acceptable alternative to the original format.