How to eliminate duplicate XML namespace definitions?

I often come across XML where the same namespace is defined multiple times, instead of only at a parent element of the elements where it is needed.

Is there a simple method/tool for extracting all namespace definitions in an XML and relocating each of these definitions to a node such that each namespace is defined only once? Preferably also with an option for all nodes to be prefixed with their namespace (rather than using a default namespace from some parent). I find this would yield more human readable XML.

As an example, how could one automatically translate this

<m:Albums xmlns:m="http://ift.tt/1wqb3QJ">
  <m:Album xmlns:m="http://ift.tt/1wqb3QJ">
    <m:Artist xmlns:m="http://ift.tt/1wqb3QJ">
      <c:Name xmlns:c="http://ift.tt/1DkCl2v">
        Sting
      </c:Name>
    </m:Artist>
    <m:Title>
      Mercury Falling
    </m:Title>
  </m:Album>
  <Album xmlns="http://ift.tt/1wqb3QJ">
    <Artist>
      <c:Name xmlns:c="http://ift.tt/1DkCl2v">
        Maria Mena
      </c:Name>
    </Artist>
    <Title xmlns="http://ift.tt/1wqb3QJ">
      Weapon in Mind
    </Title>
  </Album>
</m:Albums>

into this?

<m:Albums xmlns:m="http://ift.tt/1wqb3QJ" xmlns:c="http://ift.tt/1DkCl2v">
  <m:Album>
    <m:Artist>
      <c:Name>
        Sting
      </c:Name>
    </m:Artist>
    <m:Title>
      Mercury Falling
    </m:Title>
  </m:Album>
  <m:Album>
    <m:Artist>
      <c:Name>
        Maria Mena
      </c:Name>
    </m:Artist>
    <m:Title>
      Weapon in Mind
    </m:Title>
  </m:Album>
</m:Albums>